input.py

import sys

def _euclid(a,b):
    if(b==0):
       return a
    else:
       return _euclid(b,a%b)
def _euclid_it(a,b):
    while(b):
       r = a % b
       a = b
       b = r
    return a           
def main():
	a=int(input("a="))
	b=int(input("b="))
	#line = sys.stdin.readline()
	#ab = line.split("\n")[0]
	#ab = ab.split(" ")
	#a = int(ab[0])
	#b = int(ab[1])
	print _euclid_it(a,b)

main()