a=int(input())
b=int(input())
def g(a,b):
while 1:
a,b=b,a%b
if b==0:
break
return a
print(g(a,b))
YT1pbnQoaW5wdXQoKSkKYj1pbnQoaW5wdXQoKSkKZGVmIGcoYSxiKToKICAgIHdoaWxlIDE6CiAgICAgICAgYSxiPWIsYSViCiAgICAgICAgaWYgYj09MDoKICAgICAgICAgICAgYnJlYWsKICAgIHJldHVybiBhCnByaW50KGcoYSxiKSk=