Python extend greatest common divisor

gistfile1.py

import sys
import itertools

def extend_gcd(a, b):
    if b == 0:
        return (1, 0, a)
    else:
        (a1, b1, g) = extend_gcd(b, a % b)
        return (b1, a1 - (a // b) * b1, g)
    
    
if __name__ == '__main__':
    line = sys.stdin.readline()
    a,b = line.split()
    a,b = int(a), int(b)
    
    (x, y, g) = extend_gcd(a, b)
    
    
    sys.stdout.write(str(x) + ' '  + str(y) +  '\n')