gcd.py

def gcd(a, b):
  while a!=0 and b!=0:
    if a > b:
        a = a % b
    else:
        b = b % a
  return a + b

def main():
    a, b = map(int, input().split())
    print(gcd(a, b))


if __name__ == "__main__":
    main()