def get_algo(mining_pool):

    """
    Retrieves algo when passed mining pool URL.
    Very often the algo and coin are actually in the POOL URL.

    Returns:
        String

    """

    # returns the algorithm string
    algo = None

    if mining_pool is not None:
        x = mining_pool.count('.')
        if x >= 3:
            algo = mining_pool.split(".")[0]

    return algo