# your code goes here
def gcd(a,b):
if b==0:
return a
a,b= b,a%b
gcd(a,b)
a,b = map(int,input().split())
print(gcd(a,b))
IyB5b3VyIGNvZGUgZ29lcyBoZXJlCmRlZiBnY2QoYSxiKToKCWlmIGI9PTA6CgkJcmV0dXJuIGEKCWEsYj0gYixhJWIKCWdjZChhLGIpCgphLGIgPSBtYXAoaW50LGlucHV0KCkuc3BsaXQoKSkKcHJpbnQoZ2NkKGEsYikp