from string import ascii_lowercase


def parse(filename: str) -> list[tuple[str, str, str]]:
    groups = []
    i = 0
    group = []
    with open(filename) as f:
        for line in f.readlines():
            if i % 3 == 0 and i != 0:
                groups.append(group)
                group = []
            group.append(line[:-1])
            i += 1
        groups.append(group)
    return tuple(groups)


def convert(char: str) -> int:
    return ord(char) - 96 if char in ascii_lowercase else ord(char) - 38


def common_character(group: tuple[str, str, str]) -> str:
    assert len(group) == 3
    b1, b2, b3 = group
    return filter(lambda c: c in b2 and c in b3, b1).__next__()


def solve(groups: list[tuple[str, str, str]]) -> int:
    return sum(map(convert, map(common_character, groups)))


def main():
    print(solve(parse("input")))


if __name__ == "__main__":
    main()