# your code goes here
def GCD(x, y):
print(x)
print(y)
print('\n')
if y is 0 :
return x
GCD(y, x % y)
k = GCD(980, 1000)
print(k)
IyB5b3VyIGNvZGUgZ29lcyBoZXJlCgpkZWYgR0NEKHgsIHkpOgoJcHJpbnQoeCkKCXByaW50KHkpCglwcmludCgnXG4nKQoJaWYgeSBpcyAwIDoKCQlyZXR1cm4geAoJR0NEKHksIHggJSB5KQoJCmsgPSBHQ0QoOTgwLCAxMDAwKQpwcmludChrKQ==