Euclidean algorithm for computing greatest common divisor (GCD)
# Uses python3
def Euclid_GCD(a, b):
if b == 0:
return a
a_prime = a%b
return Euclid_GCD(b,a_prime)
input = input()
a, b = map(int, input.split())
print(Euclid_GCD(a, b))