from collections import Counter


def solve_part_one(id_list: list) -> int:
    """
    Calculates the checksum for a list of IDs
    :param id_list: Python list containing a list of ID strings
    :return: Checksum as defined by the problem
    """

    twos, threes = 0, 0
    for id in id_list:
        id_counter = Counter(id)
        if 2 in id_counter.values():
            twos += 1
        if 3 in id_counter.values():
            threes += 1

    checksum = twos * threes

    return checksum