def sum_multiples_of_3_and_5(limit: int) -> int:
    """
    Sums all multiples of 3 and 5 below the provided limit.
    :param limit: Limit for multiples to search, non-inclusive.
    :return: Sum of all multiples.
    """
    # Sum the multiples of 3 and 5, but subtract the multiples of 15 which get counted
    # twice.
    return sum(range(0, limit, 3)) + sum(range(0, limit, 5)) - sum(range(0, limit, 15))