diff --git a/src/main/scala/jp/co/dwango/s99/P01.scala b/src/main/scala/s99/P01.scala
similarity index 88%
rename from src/main/scala/jp/co/dwango/s99/P01.scala
rename to src/main/scala/s99/P01.scala
index b052edb..666875e 100644
--- a/src/main/scala/jp/co/dwango/s99/P01.scala
+++ b/src/main/scala/s99/P01.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P01 {
   def last[T](list: List[T]): T =
diff --git a/src/main/scala/jp/co/dwango/s99/P02.scala b/src/main/scala/s99/P02.scala
similarity index 91%
rename from src/main/scala/jp/co/dwango/s99/P02.scala
rename to src/main/scala/s99/P02.scala
index a8aed29..2c7732e 100644
--- a/src/main/scala/jp/co/dwango/s99/P02.scala
+++ b/src/main/scala/s99/P02.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P02 {
   def penultimate[T](list: List[T]): T =
diff --git a/src/main/scala/jp/co/dwango/s99/P03.scala b/src/main/scala/s99/P03.scala
similarity index 89%
rename from src/main/scala/jp/co/dwango/s99/P03.scala
rename to src/main/scala/s99/P03.scala
index 92ed21c..20a67cb 100644
--- a/src/main/scala/jp/co/dwango/s99/P03.scala
+++ b/src/main/scala/s99/P03.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P03 {
   def nth[T](index: Int, list: List[T]): T =
diff --git a/src/main/scala/jp/co/dwango/s99/P04.scala b/src/main/scala/s99/P04.scala
similarity index 90%
rename from src/main/scala/jp/co/dwango/s99/P04.scala
rename to src/main/scala/s99/P04.scala
index e053668..21b2c15 100644
--- a/src/main/scala/jp/co/dwango/s99/P04.scala
+++ b/src/main/scala/s99/P04.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import scala.annotation.tailrec
 
diff --git a/src/main/scala/jp/co/dwango/s99/P05.scala b/src/main/scala/s99/P05.scala
similarity index 91%
rename from src/main/scala/jp/co/dwango/s99/P05.scala
rename to src/main/scala/s99/P05.scala
index e61157f..82eb53a 100644
--- a/src/main/scala/jp/co/dwango/s99/P05.scala
+++ b/src/main/scala/s99/P05.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import scala.annotation.tailrec
 
diff --git a/src/main/scala/jp/co/dwango/s99/P06.scala b/src/main/scala/s99/P06.scala
similarity index 82%
rename from src/main/scala/jp/co/dwango/s99/P06.scala
rename to src/main/scala/s99/P06.scala
index c13671f..db1b9e4 100644
--- a/src/main/scala/jp/co/dwango/s99/P06.scala
+++ b/src/main/scala/s99/P06.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P05.reverse
 
diff --git a/src/main/scala/jp/co/dwango/s99/P07.scala b/src/main/scala/s99/P07.scala
similarity index 90%
rename from src/main/scala/jp/co/dwango/s99/P07.scala
rename to src/main/scala/s99/P07.scala
index 8d1dcbe..2ec97c1 100644
--- a/src/main/scala/jp/co/dwango/s99/P07.scala
+++ b/src/main/scala/s99/P07.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P07 {
   def flatten(list: List[Any]): List[Any] =
diff --git a/src/main/scala/jp/co/dwango/s99/P08.scala b/src/main/scala/s99/P08.scala
similarity index 94%
rename from src/main/scala/jp/co/dwango/s99/P08.scala
rename to src/main/scala/s99/P08.scala
index faee796..7e9e47b 100644
--- a/src/main/scala/jp/co/dwango/s99/P08.scala
+++ b/src/main/scala/s99/P08.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P08 {
   def compress[T](list: List[T]): List[T] = {
diff --git a/src/main/scala/jp/co/dwango/s99/P09.scala b/src/main/scala/s99/P09.scala
similarity index 90%
rename from src/main/scala/jp/co/dwango/s99/P09.scala
rename to src/main/scala/s99/P09.scala
index 1c4a71c..271b2e0 100644
--- a/src/main/scala/jp/co/dwango/s99/P09.scala
+++ b/src/main/scala/s99/P09.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P09 {
   def pack[T](list: List[T]): List[List[T]] =
diff --git a/src/main/scala/jp/co/dwango/s99/P10.scala b/src/main/scala/s99/P10.scala
similarity index 93%
rename from src/main/scala/jp/co/dwango/s99/P10.scala
rename to src/main/scala/s99/P10.scala
index dc06918..8256fed 100644
--- a/src/main/scala/jp/co/dwango/s99/P10.scala
+++ b/src/main/scala/s99/P10.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P04.length
 import P05.reverse
diff --git a/src/main/scala/jp/co/dwango/s99/P11.scala b/src/main/scala/s99/P11.scala
similarity index 90%
rename from src/main/scala/jp/co/dwango/s99/P11.scala
rename to src/main/scala/s99/P11.scala
index e0bf3d1..2da329c 100644
--- a/src/main/scala/jp/co/dwango/s99/P11.scala
+++ b/src/main/scala/s99/P11.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import Util.map
 import P04.length
diff --git a/src/main/scala/jp/co/dwango/s99/P12.scala b/src/main/scala/s99/P12.scala
similarity index 86%
rename from src/main/scala/jp/co/dwango/s99/P12.scala
rename to src/main/scala/s99/P12.scala
index 3d48e79..92ae0f9 100644
--- a/src/main/scala/jp/co/dwango/s99/P12.scala
+++ b/src/main/scala/s99/P12.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import Util.flatMap
 import Util.copyN
diff --git a/src/main/scala/jp/co/dwango/s99/P13.scala b/src/main/scala/s99/P13.scala
similarity index 94%
rename from src/main/scala/jp/co/dwango/s99/P13.scala
rename to src/main/scala/s99/P13.scala
index adf2200..73326d3 100644
--- a/src/main/scala/jp/co/dwango/s99/P13.scala
+++ b/src/main/scala/s99/P13.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P13 {
   def encodeDirect[T](list: List[T]): List[(Int, T)] = {
diff --git a/src/main/scala/jp/co/dwango/s99/P14.scala b/src/main/scala/s99/P14.scala
similarity index 83%
rename from src/main/scala/jp/co/dwango/s99/P14.scala
rename to src/main/scala/s99/P14.scala
index c1a9a90..b32349c 100644
--- a/src/main/scala/jp/co/dwango/s99/P14.scala
+++ b/src/main/scala/s99/P14.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import Util.flatMap
 
diff --git a/src/main/scala/jp/co/dwango/s99/P15.scala b/src/main/scala/s99/P15.scala
similarity index 86%
rename from src/main/scala/jp/co/dwango/s99/P15.scala
rename to src/main/scala/s99/P15.scala
index c1e176f..2af337c 100644
--- a/src/main/scala/jp/co/dwango/s99/P15.scala
+++ b/src/main/scala/s99/P15.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import Util.flatMap
 import Util.copyN
diff --git a/src/main/scala/jp/co/dwango/s99/P16.scala b/src/main/scala/s99/P16.scala
similarity index 93%
rename from src/main/scala/jp/co/dwango/s99/P16.scala
rename to src/main/scala/s99/P16.scala
index 511f957..8cb4a05 100644
--- a/src/main/scala/jp/co/dwango/s99/P16.scala
+++ b/src/main/scala/s99/P16.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P16 {
   def drop[T](nth: Int, list: List[T]): List[T] = {
diff --git a/src/main/scala/jp/co/dwango/s99/P17.scala b/src/main/scala/s99/P17.scala
similarity index 91%
rename from src/main/scala/jp/co/dwango/s99/P17.scala
rename to src/main/scala/s99/P17.scala
index b1a6b4e..35c2b85 100644
--- a/src/main/scala/jp/co/dwango/s99/P17.scala
+++ b/src/main/scala/s99/P17.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P17 {
   def split[T](n: Int, list: List[T]): (List[T], List[T]) =
diff --git a/src/main/scala/jp/co/dwango/s99/P18.scala b/src/main/scala/s99/P18.scala
similarity index 94%
rename from src/main/scala/jp/co/dwango/s99/P18.scala
rename to src/main/scala/s99/P18.scala
index c3a077d..70e0077 100644
--- a/src/main/scala/jp/co/dwango/s99/P18.scala
+++ b/src/main/scala/s99/P18.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P18 {
   def slice[T](i: Int, k: Int, list: List[T]): List[T] = {
diff --git a/src/main/scala/jp/co/dwango/s99/P19.scala b/src/main/scala/s99/P19.scala
similarity index 96%
rename from src/main/scala/jp/co/dwango/s99/P19.scala
rename to src/main/scala/s99/P19.scala
index b48ee78..ec5dc23 100644
--- a/src/main/scala/jp/co/dwango/s99/P19.scala
+++ b/src/main/scala/s99/P19.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P05.reverse
 import Util.append
diff --git a/src/main/scala/jp/co/dwango/s99/P20.scala b/src/main/scala/s99/P20.scala
similarity index 91%
rename from src/main/scala/jp/co/dwango/s99/P20.scala
rename to src/main/scala/s99/P20.scala
index 98a7db8..6d1eff8 100644
--- a/src/main/scala/jp/co/dwango/s99/P20.scala
+++ b/src/main/scala/s99/P20.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P20 {
   def removeAt[T](nth: Int, list: List[T]): (List[T], T) =
diff --git a/src/main/scala/jp/co/dwango/s99/P21.scala b/src/main/scala/s99/P21.scala
similarity index 91%
rename from src/main/scala/jp/co/dwango/s99/P21.scala
rename to src/main/scala/s99/P21.scala
index 4fd9ccf..1dfd78d 100644
--- a/src/main/scala/jp/co/dwango/s99/P21.scala
+++ b/src/main/scala/s99/P21.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P21 {
   def insertAt[T](e: T, index: Int, list: List[T]): List[T] =
diff --git a/src/main/scala/jp/co/dwango/s99/P22.scala b/src/main/scala/s99/P22.scala
similarity index 92%
rename from src/main/scala/jp/co/dwango/s99/P22.scala
rename to src/main/scala/s99/P22.scala
index cfcc0a3..d9ad74f 100644
--- a/src/main/scala/jp/co/dwango/s99/P22.scala
+++ b/src/main/scala/s99/P22.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P22 {
   def range(from: Int, to: Int): List[Int] = {
diff --git a/src/main/scala/jp/co/dwango/s99/P23.scala b/src/main/scala/s99/P23.scala
similarity index 95%
rename from src/main/scala/jp/co/dwango/s99/P23.scala
rename to src/main/scala/s99/P23.scala
index 03c69a6..42f42f9 100644
--- a/src/main/scala/jp/co/dwango/s99/P23.scala
+++ b/src/main/scala/s99/P23.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P04.length
 import P20.removeAt
diff --git a/src/main/scala/jp/co/dwango/s99/P24.scala b/src/main/scala/s99/P24.scala
similarity index 83%
rename from src/main/scala/jp/co/dwango/s99/P24.scala
rename to src/main/scala/s99/P24.scala
index 2252f30..352fc6d 100644
--- a/src/main/scala/jp/co/dwango/s99/P24.scala
+++ b/src/main/scala/s99/P24.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P22.range
 import P23.randomSelect
diff --git a/src/main/scala/jp/co/dwango/s99/P25.scala b/src/main/scala/s99/P25.scala
similarity index 85%
rename from src/main/scala/jp/co/dwango/s99/P25.scala
rename to src/main/scala/s99/P25.scala
index a39ce4d..288e2fc 100644
--- a/src/main/scala/jp/co/dwango/s99/P25.scala
+++ b/src/main/scala/s99/P25.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P04.length
 import P23.randomSelect
diff --git a/src/main/scala/jp/co/dwango/s99/P26.scala b/src/main/scala/s99/P26.scala
similarity index 96%
rename from src/main/scala/jp/co/dwango/s99/P26.scala
rename to src/main/scala/s99/P26.scala
index a7a830a..0606fef 100644
--- a/src/main/scala/jp/co/dwango/s99/P26.scala
+++ b/src/main/scala/s99/P26.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import Util.append
 import Util.map
diff --git a/src/main/scala/jp/co/dwango/s99/P27a.scala b/src/main/scala/s99/P27a.scala
similarity index 92%
rename from src/main/scala/jp/co/dwango/s99/P27a.scala
rename to src/main/scala/s99/P27a.scala
index 3d28fbc..b4ef67b 100644
--- a/src/main/scala/jp/co/dwango/s99/P27a.scala
+++ b/src/main/scala/s99/P27a.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import Util.flatMap
 import Util.map
diff --git a/src/main/scala/jp/co/dwango/s99/P27b.scala b/src/main/scala/s99/P27b.scala
similarity index 95%
rename from src/main/scala/jp/co/dwango/s99/P27b.scala
rename to src/main/scala/s99/P27b.scala
index e0142e3..bae9319 100644
--- a/src/main/scala/jp/co/dwango/s99/P27b.scala
+++ b/src/main/scala/s99/P27b.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import Util.flatMap
 import Util.map
diff --git a/src/main/scala/jp/co/dwango/s99/P28a.scala b/src/main/scala/s99/P28a.scala
similarity index 97%
rename from src/main/scala/jp/co/dwango/s99/P28a.scala
rename to src/main/scala/s99/P28a.scala
index 81d452a..e009de1 100644
--- a/src/main/scala/jp/co/dwango/s99/P28a.scala
+++ b/src/main/scala/s99/P28a.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import Util.map
 import Util.split
diff --git a/src/main/scala/jp/co/dwango/s99/P28b.scala b/src/main/scala/s99/P28b.scala
similarity index 94%
rename from src/main/scala/jp/co/dwango/s99/P28b.scala
rename to src/main/scala/s99/P28b.scala
index 2774770..b9d763c 100644
--- a/src/main/scala/jp/co/dwango/s99/P28b.scala
+++ b/src/main/scala/s99/P28b.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import Util.map
 import Util.foldLeft
diff --git a/src/main/scala/jp/co/dwango/s99/P31.scala b/src/main/scala/s99/P31.scala
similarity index 88%
rename from src/main/scala/jp/co/dwango/s99/P31.scala
rename to src/main/scala/s99/P31.scala
index db292d8..6caa503 100644
--- a/src/main/scala/jp/co/dwango/s99/P31.scala
+++ b/src/main/scala/s99/P31.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P31 {
   implicit class RichInt(self: Int) {
diff --git a/src/main/scala/jp/co/dwango/s99/P32.scala b/src/main/scala/s99/P32.scala
similarity index 93%
rename from src/main/scala/jp/co/dwango/s99/P32.scala
rename to src/main/scala/s99/P32.scala
index 18c5567..7af7a57 100644
--- a/src/main/scala/jp/co/dwango/s99/P32.scala
+++ b/src/main/scala/s99/P32.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P32 {
   def gcd(x: Int, y: Int): Int = {
diff --git a/src/main/scala/jp/co/dwango/s99/P33.scala b/src/main/scala/s99/P33.scala
similarity index 82%
rename from src/main/scala/jp/co/dwango/s99/P33.scala
rename to src/main/scala/s99/P33.scala
index f7db655..130cff9 100644
--- a/src/main/scala/jp/co/dwango/s99/P33.scala
+++ b/src/main/scala/s99/P33.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P33 {
   implicit class RichInt(self: Int) {
diff --git a/src/main/scala/jp/co/dwango/s99/P46.scala b/src/main/scala/s99/P46.scala
similarity index 95%
rename from src/main/scala/jp/co/dwango/s99/P46.scala
rename to src/main/scala/s99/P46.scala
index f2e4233..afe4c3a 100644
--- a/src/main/scala/jp/co/dwango/s99/P46.scala
+++ b/src/main/scala/s99/P46.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P46 {
   def and(x: Boolean, y: Boolean): Boolean = x & y
diff --git a/src/main/scala/jp/co/dwango/s99/P47.scala b/src/main/scala/s99/P47.scala
similarity index 95%
rename from src/main/scala/jp/co/dwango/s99/P47.scala
rename to src/main/scala/s99/P47.scala
index 075ce97..3b3e919 100644
--- a/src/main/scala/jp/co/dwango/s99/P47.scala
+++ b/src/main/scala/s99/P47.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P47 {
   implicit class RichBoolean(val self: Boolean) extends AnyVal {
diff --git a/src/main/scala/jp/co/dwango/s99/P49.scala b/src/main/scala/s99/P49.scala
similarity index 95%
rename from src/main/scala/jp/co/dwango/s99/P49.scala
rename to src/main/scala/s99/P49.scala
index 7cf13f5..f4cbd9f 100644
--- a/src/main/scala/jp/co/dwango/s99/P49.scala
+++ b/src/main/scala/s99/P49.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import scala.collection.mutable
 
diff --git a/src/main/scala/jp/co/dwango/s99/P55.scala b/src/main/scala/s99/P55.scala
similarity index 90%
rename from src/main/scala/jp/co/dwango/s99/P55.scala
rename to src/main/scala/s99/P55.scala
index 240e80f..0203236 100644
--- a/src/main/scala/jp/co/dwango/s99/P55.scala
+++ b/src/main/scala/s99/P55.scala
@@ -1,5 +1,5 @@
-package jp.co.dwango.s99
-import jp.co.dwango.s99.binary_trees._
+package s99
+import s99.binary_trees._
 
 object P55 {
   object Tree {
diff --git a/src/main/scala/jp/co/dwango/s99/P56.scala b/src/main/scala/s99/P56.scala
similarity index 88%
rename from src/main/scala/jp/co/dwango/s99/P56.scala
rename to src/main/scala/s99/P56.scala
index d434092..04c1e53 100644
--- a/src/main/scala/jp/co/dwango/s99/P56.scala
+++ b/src/main/scala/s99/P56.scala
@@ -1,5 +1,5 @@
-package jp.co.dwango.s99
-import jp.co.dwango.s99.binary_trees._
+package s99
+import s99.binary_trees._
 
 object P56 {
   implicit class RichTree[T](val tree: Tree[T]) extends AnyVal {
diff --git a/src/main/scala/jp/co/dwango/s99/P57.scala b/src/main/scala/s99/P57.scala
similarity index 82%
rename from src/main/scala/jp/co/dwango/s99/P57.scala
rename to src/main/scala/s99/P57.scala
index 7562d52..925dff1 100644
--- a/src/main/scala/jp/co/dwango/s99/P57.scala
+++ b/src/main/scala/s99/P57.scala
@@ -1,8 +1,8 @@
-package jp.co.dwango.s99
+package s99
 
-import jp.co.dwango.s99.binary_trees.Tree
-import jp.co.dwango.s99.binary_trees.Node
-import jp.co.dwango.s99.binary_trees.End
+import s99.binary_trees.Tree
+import s99.binary_trees.Node
+import s99.binary_trees.End
 
 object P57 {
   implicit class RichTree[T](self: Tree[T]) {
diff --git a/src/main/scala/jp/co/dwango/s99/P58.scala b/src/main/scala/s99/P58.scala
similarity index 77%
rename from src/main/scala/jp/co/dwango/s99/P58.scala
rename to src/main/scala/s99/P58.scala
index 26dd30e..2c17fe4 100644
--- a/src/main/scala/jp/co/dwango/s99/P58.scala
+++ b/src/main/scala/s99/P58.scala
@@ -1,6 +1,6 @@
-package jp.co.dwango.s99
+package s99
 
-import jp.co.dwango.s99.binary_trees.{Tree}
+import s99.binary_trees.{Tree}
 import P56._
 
 object P58 {
diff --git a/src/main/scala/jp/co/dwango/s99/P61.scala b/src/main/scala/s99/P61.scala
similarity index 92%
rename from src/main/scala/jp/co/dwango/s99/P61.scala
rename to src/main/scala/s99/P61.scala
index 67ccb3c..4d0a2aa 100644
--- a/src/main/scala/jp/co/dwango/s99/P61.scala
+++ b/src/main/scala/s99/P61.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 import binary_trees._
 
 object P61 {
diff --git a/src/main/scala/jp/co/dwango/s99/P61a.scala b/src/main/scala/s99/P61a.scala
similarity index 95%
rename from src/main/scala/jp/co/dwango/s99/P61a.scala
rename to src/main/scala/s99/P61a.scala
index 283f6bd..244da6e 100644
--- a/src/main/scala/jp/co/dwango/s99/P61a.scala
+++ b/src/main/scala/s99/P61a.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 import binary_trees._
 
 import scala.annotation.tailrec
diff --git a/src/main/scala/jp/co/dwango/s99/P62.scala b/src/main/scala/s99/P62.scala
similarity index 92%
rename from src/main/scala/jp/co/dwango/s99/P62.scala
rename to src/main/scala/s99/P62.scala
index bcd2a7d..808e757 100644
--- a/src/main/scala/jp/co/dwango/s99/P62.scala
+++ b/src/main/scala/s99/P62.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 import binary_trees._
 
 object P62 {
diff --git a/src/main/scala/jp/co/dwango/s99/P62b.scala b/src/main/scala/s99/P62b.scala
similarity index 94%
rename from src/main/scala/jp/co/dwango/s99/P62b.scala
rename to src/main/scala/s99/P62b.scala
index 1b2a8e7..a573482 100644
--- a/src/main/scala/jp/co/dwango/s99/P62b.scala
+++ b/src/main/scala/s99/P62b.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 import binary_trees._
 
 object P62b {
diff --git a/src/main/scala/jp/co/dwango/s99/P67.scala b/src/main/scala/s99/P67.scala
similarity index 99%
rename from src/main/scala/jp/co/dwango/s99/P67.scala
rename to src/main/scala/s99/P67.scala
index 4f9bd3e..c42aabb 100644
--- a/src/main/scala/jp/co/dwango/s99/P67.scala
+++ b/src/main/scala/s99/P67.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 import binary_trees._
 
 object P67 {
diff --git a/src/main/scala/jp/co/dwango/s99/P68.scala b/src/main/scala/s99/P68.scala
similarity index 88%
rename from src/main/scala/jp/co/dwango/s99/P68.scala
rename to src/main/scala/s99/P68.scala
index 3c9a6f2..f92b819 100644
--- a/src/main/scala/jp/co/dwango/s99/P68.scala
+++ b/src/main/scala/s99/P68.scala
@@ -1,6 +1,6 @@
-package jp.co.dwango.s99
+package s99
 
-import jp.co.dwango.s99.binary_trees._
+import s99.binary_trees._
 
 object P68 {
   implicit class RichTree[T](tree: Tree[T]) {
diff --git a/src/main/scala/jp/co/dwango/s99/P90.scala b/src/main/scala/s99/P90.scala
similarity index 98%
rename from src/main/scala/jp/co/dwango/s99/P90.scala
rename to src/main/scala/s99/P90.scala
index fb9965b..4530b90 100644
--- a/src/main/scala/jp/co/dwango/s99/P90.scala
+++ b/src/main/scala/s99/P90.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import scala.collection.mutable.ListBuffer
 
diff --git a/src/main/scala/jp/co/dwango/s99/P96.scala b/src/main/scala/s99/P96.scala
similarity index 98%
rename from src/main/scala/jp/co/dwango/s99/P96.scala
rename to src/main/scala/s99/P96.scala
index c933a8e..ba6efe0 100644
--- a/src/main/scala/jp/co/dwango/s99/P96.scala
+++ b/src/main/scala/s99/P96.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object P96 {
   /*
diff --git a/src/main/scala/jp/co/dwango/s99/Util.scala b/src/main/scala/s99/Util.scala
similarity index 97%
rename from src/main/scala/jp/co/dwango/s99/Util.scala
rename to src/main/scala/s99/Util.scala
index 69a8226..c9ab7f3 100644
--- a/src/main/scala/jp/co/dwango/s99/Util.scala
+++ b/src/main/scala/s99/Util.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 object Util {
   def append[T](a: List[T], b: List[T]): List[T] =
diff --git a/src/main/scala/jp/co/dwango/s99/arithmetic/package.scala b/src/main/scala/s99/arithmetic/package.scala
similarity index 96%
rename from src/main/scala/jp/co/dwango/s99/arithmetic/package.scala
rename to src/main/scala/s99/arithmetic/package.scala
index 5c39499..dd7a143 100644
--- a/src/main/scala/jp/co/dwango/s99/arithmetic/package.scala
+++ b/src/main/scala/s99/arithmetic/package.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P10.encode
 
diff --git a/src/main/scala/jp/co/dwango/s99/binary_trees/Tree.scala b/src/main/scala/s99/binary_trees/Tree.scala
similarity index 90%
rename from src/main/scala/jp/co/dwango/s99/binary_trees/Tree.scala
rename to src/main/scala/s99/binary_trees/Tree.scala
index b26f527..1202342 100644
--- a/src/main/scala/jp/co/dwango/s99/binary_trees/Tree.scala
+++ b/src/main/scala/s99/binary_trees/Tree.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99.binary_trees
+package s99.binary_trees
 
 sealed abstract class Tree[+T]
 case class Node[+T](value: T, left: Tree[T], right: Tree[T]) extends Tree[T] {
diff --git a/src/test/scala/jp/co/dwango/s99/P01Check.scala b/src/test/scala/s99/P01Check.scala
similarity index 90%
rename from src/test/scala/jp/co/dwango/s99/P01Check.scala
rename to src/test/scala/s99/P01Check.scala
index 0adc49b..f80e1b9 100644
--- a/src/test/scala/jp/co/dwango/s99/P01Check.scala
+++ b/src/test/scala/s99/P01Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.Properties
 import org.scalacheck.Prop.{forAll, propBoolean}
diff --git a/src/test/scala/jp/co/dwango/s99/P01Spec.scala b/src/test/scala/s99/P01Spec.scala
similarity index 93%
rename from src/test/scala/jp/co/dwango/s99/P01Spec.scala
rename to src/test/scala/s99/P01Spec.scala
index 01fcc0b..f4fefd8 100644
--- a/src/test/scala/jp/co/dwango/s99/P01Spec.scala
+++ b/src/test/scala/s99/P01Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P02Check.scala b/src/test/scala/s99/P02Check.scala
similarity index 91%
rename from src/test/scala/jp/co/dwango/s99/P02Check.scala
rename to src/test/scala/s99/P02Check.scala
index acddc25..98e8bb8 100644
--- a/src/test/scala/jp/co/dwango/s99/P02Check.scala
+++ b/src/test/scala/s99/P02Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.Properties
 import org.scalacheck.Prop.{forAll, propBoolean}
diff --git a/src/test/scala/jp/co/dwango/s99/P02Spec.scala b/src/test/scala/s99/P02Spec.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P02Spec.scala
rename to src/test/scala/s99/P02Spec.scala
index 1e8a42c..c1f9331 100644
--- a/src/test/scala/jp/co/dwango/s99/P02Spec.scala
+++ b/src/test/scala/s99/P02Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P03Check.scala b/src/test/scala/s99/P03Check.scala
similarity index 93%
rename from src/test/scala/jp/co/dwango/s99/P03Check.scala
rename to src/test/scala/s99/P03Check.scala
index 6db6397..cb61b79 100644
--- a/src/test/scala/jp/co/dwango/s99/P03Check.scala
+++ b/src/test/scala/s99/P03Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Arbitrary, Gen, Prop, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P03Spec.scala b/src/test/scala/s99/P03Spec.scala
similarity index 97%
rename from src/test/scala/jp/co/dwango/s99/P03Spec.scala
rename to src/test/scala/s99/P03Spec.scala
index 7a238d0..97337ba 100644
--- a/src/test/scala/jp/co/dwango/s99/P03Spec.scala
+++ b/src/test/scala/s99/P03Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P04Check.scala b/src/test/scala/s99/P04Check.scala
similarity index 88%
rename from src/test/scala/jp/co/dwango/s99/P04Check.scala
rename to src/test/scala/s99/P04Check.scala
index d4cbedc..c4d5368 100644
--- a/src/test/scala/jp/co/dwango/s99/P04Check.scala
+++ b/src/test/scala/s99/P04Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.Properties
 import org.scalacheck.Prop.forAll
diff --git a/src/test/scala/jp/co/dwango/s99/P04Spec.scala b/src/test/scala/s99/P04Spec.scala
similarity index 93%
rename from src/test/scala/jp/co/dwango/s99/P04Spec.scala
rename to src/test/scala/s99/P04Spec.scala
index 622dd63..1f2d635 100644
--- a/src/test/scala/jp/co/dwango/s99/P04Spec.scala
+++ b/src/test/scala/s99/P04Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P05Check.scala b/src/test/scala/s99/P05Check.scala
similarity index 89%
rename from src/test/scala/jp/co/dwango/s99/P05Check.scala
rename to src/test/scala/s99/P05Check.scala
index e5f61d9..cf2a515 100644
--- a/src/test/scala/jp/co/dwango/s99/P05Check.scala
+++ b/src/test/scala/s99/P05Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.Properties
 import org.scalacheck.Prop.forAll
diff --git a/src/test/scala/jp/co/dwango/s99/P05Spec.scala b/src/test/scala/s99/P05Spec.scala
similarity index 94%
rename from src/test/scala/jp/co/dwango/s99/P05Spec.scala
rename to src/test/scala/s99/P05Spec.scala
index fd2cd01..cf3585b 100644
--- a/src/test/scala/jp/co/dwango/s99/P05Spec.scala
+++ b/src/test/scala/s99/P05Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P06Check.scala b/src/test/scala/s99/P06Check.scala
similarity index 93%
rename from src/test/scala/jp/co/dwango/s99/P06Check.scala
rename to src/test/scala/s99/P06Check.scala
index 3606010..4016d47 100644
--- a/src/test/scala/jp/co/dwango/s99/P06Check.scala
+++ b/src/test/scala/s99/P06Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Gen, Properties}
 import Gen.listOf, Gen.chooseNum
diff --git a/src/test/scala/jp/co/dwango/s99/P06Spec.scala b/src/test/scala/s99/P06Spec.scala
similarity index 94%
rename from src/test/scala/jp/co/dwango/s99/P06Spec.scala
rename to src/test/scala/s99/P06Spec.scala
index dbbb2ba..1734b89 100644
--- a/src/test/scala/jp/co/dwango/s99/P06Spec.scala
+++ b/src/test/scala/s99/P06Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P07Check.scala b/src/test/scala/s99/P07Check.scala
similarity index 89%
rename from src/test/scala/jp/co/dwango/s99/P07Check.scala
rename to src/test/scala/s99/P07Check.scala
index db95442..7b1b49f 100644
--- a/src/test/scala/jp/co/dwango/s99/P07Check.scala
+++ b/src/test/scala/s99/P07Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.Properties
 import org.scalacheck.Prop.forAll
diff --git a/src/test/scala/jp/co/dwango/s99/P07Spec.scala b/src/test/scala/s99/P07Spec.scala
similarity index 94%
rename from src/test/scala/jp/co/dwango/s99/P07Spec.scala
rename to src/test/scala/s99/P07Spec.scala
index 5de972d..2a4a25c 100644
--- a/src/test/scala/jp/co/dwango/s99/P07Spec.scala
+++ b/src/test/scala/s99/P07Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P08Check.scala b/src/test/scala/s99/P08Check.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P08Check.scala
rename to src/test/scala/s99/P08Check.scala
index f811f1e..67a9abf 100644
--- a/src/test/scala/jp/co/dwango/s99/P08Check.scala
+++ b/src/test/scala/s99/P08Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.Prop.forAll
 import org.scalacheck.Properties
diff --git a/src/test/scala/jp/co/dwango/s99/P08Spec.scala b/src/test/scala/s99/P08Spec.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P08Spec.scala
rename to src/test/scala/s99/P08Spec.scala
index 86b1d16..616cf0f 100644
--- a/src/test/scala/jp/co/dwango/s99/P08Spec.scala
+++ b/src/test/scala/s99/P08Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P09Spec.scala b/src/test/scala/s99/P09Spec.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P09Spec.scala
rename to src/test/scala/s99/P09Spec.scala
index c68ff3a..aa8f2f3 100644
--- a/src/test/scala/jp/co/dwango/s99/P09Spec.scala
+++ b/src/test/scala/s99/P09Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P10Spec.scala b/src/test/scala/s99/P10Spec.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P10Spec.scala
rename to src/test/scala/s99/P10Spec.scala
index 295bcce..510334e 100644
--- a/src/test/scala/jp/co/dwango/s99/P10Spec.scala
+++ b/src/test/scala/s99/P10Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P11Spec.scala b/src/test/scala/s99/P11Spec.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P11Spec.scala
rename to src/test/scala/s99/P11Spec.scala
index 4f7beff..5e43077 100644
--- a/src/test/scala/jp/co/dwango/s99/P11Spec.scala
+++ b/src/test/scala/s99/P11Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P12Spec.scala b/src/test/scala/s99/P12Spec.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P12Spec.scala
rename to src/test/scala/s99/P12Spec.scala
index acaf9b4..b9d6613 100644
--- a/src/test/scala/jp/co/dwango/s99/P12Spec.scala
+++ b/src/test/scala/s99/P12Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P13Check.scala b/src/test/scala/s99/P13Check.scala
similarity index 91%
rename from src/test/scala/jp/co/dwango/s99/P13Check.scala
rename to src/test/scala/s99/P13Check.scala
index 706b1f0..3633191 100644
--- a/src/test/scala/jp/co/dwango/s99/P13Check.scala
+++ b/src/test/scala/s99/P13Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.Prop.forAll
 import org.scalacheck.Properties
diff --git a/src/test/scala/jp/co/dwango/s99/P13Spec.scala b/src/test/scala/s99/P13Spec.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P13Spec.scala
rename to src/test/scala/s99/P13Spec.scala
index ab1c70c..7c4623c 100644
--- a/src/test/scala/jp/co/dwango/s99/P13Spec.scala
+++ b/src/test/scala/s99/P13Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P14Check.scala b/src/test/scala/s99/P14Check.scala
similarity index 90%
rename from src/test/scala/jp/co/dwango/s99/P14Check.scala
rename to src/test/scala/s99/P14Check.scala
index 78d838a..c4b47df 100644
--- a/src/test/scala/jp/co/dwango/s99/P14Check.scala
+++ b/src/test/scala/s99/P14Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.Prop.forAll
 import org.scalacheck.Properties
diff --git a/src/test/scala/jp/co/dwango/s99/P14Spec.scala b/src/test/scala/s99/P14Spec.scala
similarity index 97%
rename from src/test/scala/jp/co/dwango/s99/P14Spec.scala
rename to src/test/scala/s99/P14Spec.scala
index a7c8ac3..750cc07 100644
--- a/src/test/scala/jp/co/dwango/s99/P14Spec.scala
+++ b/src/test/scala/s99/P14Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P15Spec.scala b/src/test/scala/s99/P15Spec.scala
similarity index 98%
rename from src/test/scala/jp/co/dwango/s99/P15Spec.scala
rename to src/test/scala/s99/P15Spec.scala
index 3d6b105..98ab8c6 100644
--- a/src/test/scala/jp/co/dwango/s99/P15Spec.scala
+++ b/src/test/scala/s99/P15Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P16Check.scala b/src/test/scala/s99/P16Check.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P16Check.scala
rename to src/test/scala/s99/P16Check.scala
index 0ad4e9c..201cc65 100644
--- a/src/test/scala/jp/co/dwango/s99/P16Check.scala
+++ b/src/test/scala/s99/P16Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Gen, Properties}
 import Gen.listOf, Gen.chooseNum
diff --git a/src/test/scala/jp/co/dwango/s99/P16Spec.scala b/src/test/scala/s99/P16Spec.scala
similarity index 97%
rename from src/test/scala/jp/co/dwango/s99/P16Spec.scala
rename to src/test/scala/s99/P16Spec.scala
index efaf910..cf0ebc1 100644
--- a/src/test/scala/jp/co/dwango/s99/P16Spec.scala
+++ b/src/test/scala/s99/P16Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P17Check.scala b/src/test/scala/s99/P17Check.scala
similarity index 93%
rename from src/test/scala/jp/co/dwango/s99/P17Check.scala
rename to src/test/scala/s99/P17Check.scala
index c5f489f..4486021 100644
--- a/src/test/scala/jp/co/dwango/s99/P17Check.scala
+++ b/src/test/scala/s99/P17Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Gen, Properties}
 import Gen.listOf, Gen.chooseNum
diff --git a/src/test/scala/jp/co/dwango/s99/P17Spec.scala b/src/test/scala/s99/P17Spec.scala
similarity index 98%
rename from src/test/scala/jp/co/dwango/s99/P17Spec.scala
rename to src/test/scala/s99/P17Spec.scala
index aa686f4..a0c5b1e 100644
--- a/src/test/scala/jp/co/dwango/s99/P17Spec.scala
+++ b/src/test/scala/s99/P17Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P18Check.scala b/src/test/scala/s99/P18Check.scala
similarity index 94%
rename from src/test/scala/jp/co/dwango/s99/P18Check.scala
rename to src/test/scala/s99/P18Check.scala
index 4cf26de..4088fc4 100644
--- a/src/test/scala/jp/co/dwango/s99/P18Check.scala
+++ b/src/test/scala/s99/P18Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Gen, Properties}
 import Gen.listOf, Gen.chooseNum
diff --git a/src/test/scala/jp/co/dwango/s99/P19Spec.scala b/src/test/scala/s99/P19Spec.scala
similarity index 98%
rename from src/test/scala/jp/co/dwango/s99/P19Spec.scala
rename to src/test/scala/s99/P19Spec.scala
index 0aeb6e4..2e4c08a 100644
--- a/src/test/scala/jp/co/dwango/s99/P19Spec.scala
+++ b/src/test/scala/s99/P19Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P20Check.scala b/src/test/scala/s99/P20Check.scala
similarity index 94%
rename from src/test/scala/jp/co/dwango/s99/P20Check.scala
rename to src/test/scala/s99/P20Check.scala
index 2daf477..f7f2534 100644
--- a/src/test/scala/jp/co/dwango/s99/P20Check.scala
+++ b/src/test/scala/s99/P20Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Arbitrary, Gen, Prop, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P21Check.scala b/src/test/scala/s99/P21Check.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P21Check.scala
rename to src/test/scala/s99/P21Check.scala
index 2d158d8..6e70171 100644
--- a/src/test/scala/jp/co/dwango/s99/P21Check.scala
+++ b/src/test/scala/s99/P21Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Arbitrary, Gen, Prop, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P22Check.scala b/src/test/scala/s99/P22Check.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P22Check.scala
rename to src/test/scala/s99/P22Check.scala
index 6253a55..ac2bc12 100644
--- a/src/test/scala/jp/co/dwango/s99/P22Check.scala
+++ b/src/test/scala/s99/P22Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Arbitrary, Gen, Prop, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P23Check.scala b/src/test/scala/s99/P23Check.scala
similarity index 93%
rename from src/test/scala/jp/co/dwango/s99/P23Check.scala
rename to src/test/scala/s99/P23Check.scala
index 508599e..6a45eae 100644
--- a/src/test/scala/jp/co/dwango/s99/P23Check.scala
+++ b/src/test/scala/s99/P23Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Arbitrary, Gen, Prop, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P24Check.scala b/src/test/scala/s99/P24Check.scala
similarity index 93%
rename from src/test/scala/jp/co/dwango/s99/P24Check.scala
rename to src/test/scala/s99/P24Check.scala
index a18b084..957dfa8 100644
--- a/src/test/scala/jp/co/dwango/s99/P24Check.scala
+++ b/src/test/scala/s99/P24Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Gen, Prop, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P25Check.scala b/src/test/scala/s99/P25Check.scala
similarity index 89%
rename from src/test/scala/jp/co/dwango/s99/P25Check.scala
rename to src/test/scala/s99/P25Check.scala
index 6ce5807..686f102 100644
--- a/src/test/scala/jp/co/dwango/s99/P25Check.scala
+++ b/src/test/scala/s99/P25Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Prop, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P26Check.scala b/src/test/scala/s99/P26Check.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P26Check.scala
rename to src/test/scala/s99/P26Check.scala
index 53cb1b6..93e6187 100644
--- a/src/test/scala/jp/co/dwango/s99/P26Check.scala
+++ b/src/test/scala/s99/P26Check.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Prop, Gen, Arbitrary, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P27aCheck.scala b/src/test/scala/s99/P27aCheck.scala
similarity index 94%
rename from src/test/scala/jp/co/dwango/s99/P27aCheck.scala
rename to src/test/scala/s99/P27aCheck.scala
index 2cf7284..fb5d4f5 100644
--- a/src/test/scala/jp/co/dwango/s99/P27aCheck.scala
+++ b/src/test/scala/s99/P27aCheck.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Prop, Properties, Gen}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P27bCheck.scala b/src/test/scala/s99/P27bCheck.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P27bCheck.scala
rename to src/test/scala/s99/P27bCheck.scala
index 0a367fb..8e6ae02 100644
--- a/src/test/scala/jp/co/dwango/s99/P27bCheck.scala
+++ b/src/test/scala/s99/P27bCheck.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Prop, Properties, Gen, Arbitrary}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P28aCheck.scala b/src/test/scala/s99/P28aCheck.scala
similarity index 92%
rename from src/test/scala/jp/co/dwango/s99/P28aCheck.scala
rename to src/test/scala/s99/P28aCheck.scala
index b259180..6c89f49 100644
--- a/src/test/scala/jp/co/dwango/s99/P28aCheck.scala
+++ b/src/test/scala/s99/P28aCheck.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Prop, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P28bCheck.scala b/src/test/scala/s99/P28bCheck.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P28bCheck.scala
rename to src/test/scala/s99/P28bCheck.scala
index 0577436..f8ca2c5 100644
--- a/src/test/scala/jp/co/dwango/s99/P28bCheck.scala
+++ b/src/test/scala/s99/P28bCheck.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Prop, Properties}
 
diff --git a/src/test/scala/jp/co/dwango/s99/P31Spec.scala b/src/test/scala/s99/P31Spec.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P31Spec.scala
rename to src/test/scala/s99/P31Spec.scala
index b0c7420..016537f 100644
--- a/src/test/scala/jp/co/dwango/s99/P31Spec.scala
+++ b/src/test/scala/s99/P31Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P31._
 
diff --git a/src/test/scala/jp/co/dwango/s99/P32Spec.scala b/src/test/scala/s99/P32Spec.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P32Spec.scala
rename to src/test/scala/s99/P32Spec.scala
index b1f0d44..76f6d78 100644
--- a/src/test/scala/jp/co/dwango/s99/P32Spec.scala
+++ b/src/test/scala/s99/P32Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P33Spec.scala b/src/test/scala/s99/P33Spec.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P33Spec.scala
rename to src/test/scala/s99/P33Spec.scala
index fd0825c..98b5697 100644
--- a/src/test/scala/jp/co/dwango/s99/P33Spec.scala
+++ b/src/test/scala/s99/P33Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P33.RichInt
 
diff --git a/src/test/scala/jp/co/dwango/s99/P49Spec.scala b/src/test/scala/s99/P49Spec.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P49Spec.scala
rename to src/test/scala/s99/P49Spec.scala
index 440886b..942d8dc 100644
--- a/src/test/scala/jp/co/dwango/s99/P49Spec.scala
+++ b/src/test/scala/s99/P49Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P49.gray
 import P49.gray2
diff --git a/src/test/scala/jp/co/dwango/s99/P57Check.scala b/src/test/scala/s99/P57Check.scala
similarity index 86%
rename from src/test/scala/jp/co/dwango/s99/P57Check.scala
rename to src/test/scala/s99/P57Check.scala
index b347542..dc75628 100644
--- a/src/test/scala/jp/co/dwango/s99/P57Check.scala
+++ b/src/test/scala/s99/P57Check.scala
@@ -1,10 +1,10 @@
-package jp.co.dwango.s99
+package s99
 
 import org.scalacheck.{Prop, Properties}
-import jp.co.dwango.s99.P57.Tree
-import jp.co.dwango.s99.binary_trees.Node
-import jp.co.dwango.s99.binary_trees.Tree
-import jp.co.dwango.s99.binary_trees.End
+import s99.P57.Tree
+import s99.binary_trees.Node
+import s99.binary_trees.Tree
+import s99.binary_trees.End
 
 class P57Check extends Properties("P57") {
   private type Min = Int
diff --git a/src/test/scala/jp/co/dwango/s99/P57Spec.scala b/src/test/scala/s99/P57Spec.scala
similarity index 79%
rename from src/test/scala/jp/co/dwango/s99/P57Spec.scala
rename to src/test/scala/s99/P57Spec.scala
index 1c9e611..b11741c 100644
--- a/src/test/scala/jp/co/dwango/s99/P57Spec.scala
+++ b/src/test/scala/s99/P57Spec.scala
@@ -1,7 +1,7 @@
-package jp.co.dwango.s99
+package s99
 
-import jp.co.dwango.s99.P57.Tree
-import jp.co.dwango.s99.P56._
+import s99.P57.Tree
+import s99.P56._
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P58Spec.scala b/src/test/scala/s99/P58Spec.scala
similarity index 81%
rename from src/test/scala/jp/co/dwango/s99/P58Spec.scala
rename to src/test/scala/s99/P58Spec.scala
index 562e9dc..0e6d6fe 100644
--- a/src/test/scala/jp/co/dwango/s99/P58Spec.scala
+++ b/src/test/scala/s99/P58Spec.scala
@@ -1,7 +1,7 @@
-package jp.co.dwango.s99
+package s99
 
-import jp.co.dwango.s99.P58.Tree
-import jp.co.dwango.s99.binary_trees.{Node, End}
+import s99.P58.Tree
+import s99.binary_trees.{Node, End}
 
 import org.scalatest.funspec.AnyFunSpec
 
diff --git a/src/test/scala/jp/co/dwango/s99/P61Spec.scala b/src/test/scala/s99/P61Spec.scala
similarity index 94%
rename from src/test/scala/jp/co/dwango/s99/P61Spec.scala
rename to src/test/scala/s99/P61Spec.scala
index 9656d05..dcbda2b 100644
--- a/src/test/scala/jp/co/dwango/s99/P61Spec.scala
+++ b/src/test/scala/s99/P61Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import binary_trees._
 import P61._
diff --git a/src/test/scala/jp/co/dwango/s99/P61aSpec.scala b/src/test/scala/s99/P61aSpec.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P61aSpec.scala
rename to src/test/scala/s99/P61aSpec.scala
index 419a63f..42704c6 100644
--- a/src/test/scala/jp/co/dwango/s99/P61aSpec.scala
+++ b/src/test/scala/s99/P61aSpec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import binary_trees._
 import P61a._
diff --git a/src/test/scala/jp/co/dwango/s99/P62Spec.scala b/src/test/scala/s99/P62Spec.scala
similarity index 93%
rename from src/test/scala/jp/co/dwango/s99/P62Spec.scala
rename to src/test/scala/s99/P62Spec.scala
index cc67b99..0579c96 100644
--- a/src/test/scala/jp/co/dwango/s99/P62Spec.scala
+++ b/src/test/scala/s99/P62Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import binary_trees._
 import P62._
diff --git a/src/test/scala/jp/co/dwango/s99/P62bSpec.scala b/src/test/scala/s99/P62bSpec.scala
similarity index 92%
rename from src/test/scala/jp/co/dwango/s99/P62bSpec.scala
rename to src/test/scala/s99/P62bSpec.scala
index eb12e6b..145d909 100644
--- a/src/test/scala/jp/co/dwango/s99/P62bSpec.scala
+++ b/src/test/scala/s99/P62bSpec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import binary_trees._
 import P62b._
diff --git a/src/test/scala/jp/co/dwango/s99/P67Spec.scala b/src/test/scala/s99/P67Spec.scala
similarity index 96%
rename from src/test/scala/jp/co/dwango/s99/P67Spec.scala
rename to src/test/scala/s99/P67Spec.scala
index 8c13a25..bddc812 100644
--- a/src/test/scala/jp/co/dwango/s99/P67Spec.scala
+++ b/src/test/scala/s99/P67Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P67._
 import binary_trees._
diff --git a/src/test/scala/jp/co/dwango/s99/P68Spec.scala b/src/test/scala/s99/P68Spec.scala
similarity index 95%
rename from src/test/scala/jp/co/dwango/s99/P68Spec.scala
rename to src/test/scala/s99/P68Spec.scala
index 5bad5e9..a76e9b2 100644
--- a/src/test/scala/jp/co/dwango/s99/P68Spec.scala
+++ b/src/test/scala/s99/P68Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P68._
 import binary_trees._
diff --git a/src/test/scala/jp/co/dwango/s99/P90Spec.scala b/src/test/scala/s99/P90Spec.scala
similarity index 94%
rename from src/test/scala/jp/co/dwango/s99/P90Spec.scala
rename to src/test/scala/s99/P90Spec.scala
index b7aad83..d3fc6a3 100644
--- a/src/test/scala/jp/co/dwango/s99/P90Spec.scala
+++ b/src/test/scala/s99/P90Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P90._
 
diff --git a/src/test/scala/jp/co/dwango/s99/P96Spec.scala b/src/test/scala/s99/P96Spec.scala
similarity index 97%
rename from src/test/scala/jp/co/dwango/s99/P96Spec.scala
rename to src/test/scala/s99/P96Spec.scala
index 721d38b..4ff3eea 100644
--- a/src/test/scala/jp/co/dwango/s99/P96Spec.scala
+++ b/src/test/scala/s99/P96Spec.scala
@@ -1,4 +1,4 @@
-package jp.co.dwango.s99
+package s99
 
 import P96._