扩展欧几里得求最大公因数

def solve(____):
    def extended_gcd(____):
        if a == ____:
            return b, ____, ____
        gcd, x1, y1 = extended_gcd(____)
        x = y1 - (____) * x1
        y = x1
        return gcd, x, y
    gcd, x, y = extended_gcd(____)
    print((____))