# -*- coding: utf-8 -*-
a = int(raw_input("Entrer a : "))
b = int(raw_input("Entrer b : "))

if a < b:
    tmp = b
    b = a
    a = tmp

a_orig = a
b_orig = b

while True:
    r = a % b
    if r == 0:
        break  # Sort de la boucle while
    a = b
    b = r

print "Le PGCD de", a_orig, "et", b_orig, "est", b