from typing import Counter


def part_a(puzzle_input):
    """
    Calculate the answer for part_a.

    Args:
        puzzle_input (list): Formatted as the provided input from the website.
    Returns:
        string: The answer for part_a.

    """
    twos = 0
    threes = 0
    for line in puzzle_input:
        occurrences = [n for c, n in Counter(line).most_common()]
        if 2 in occurrences:
            twos += 1
        if 3 in occurrences:
            threes += 1
    return str(twos * threes)