def gcd(a: int, b: int) -> int:
    """Greatest common divisor

    Returns greatest common divisor of given inputs using Euclid's algorithm.

    Args:
        a: First integer input.
        b: Second integer input.

    Returns:
        Integer representing GCD.
    """
    # Return the GCD of a and b using Euclid's algorithm:
    while a != 0:
        a, b = b % a, a
    return b