car_cdr.py

'''
cons(a, b) constructs a pair, and car(pair) and cdr(pair) returns the first and last element of that pair. For example, car(cons(3, 4)) returns 3, and cdr(cons(3, 4)) returns 4.
Given this implementation of cons:
Implement car and cdr.

'''
def cons(a, b):
    def pair(f):
        return f(a, b)
    return pair

def car(pair):
    return pair(lambda a, b: a)

def cdr(pair):
    return pair(lambda a, b: b)


a=int(input())
b=int(input())
print(car(cons(a,b)))
print(cdr(cons(a,b)))