a,b = map(int,input().split())
def gcd(a, b):
    if 0 in (a,b):
        return max(a,b)
    else:
        gcd(b,a%b)
if a >= b:
    print(gcd(a,b))
else:
    print(gcd(b,a))

 else:
        return gcd(b,a%b)