#!/usr/bin/env python
# -*- encoding: utf-8; py-indent-offset: 4 -*-

# Author: Sebastian Mark
# CC-BY-SA (https://creativecommons.org/licenses/by-sa/4.0/deed.de)

# pylint: disable=missing-module-docstring,missing-function-docstring,consider-using-f-string


def readinput():
    with open("input", "r", encoding="utf-8") as file:
        lines = [line.strip() for line in file.readlines()]
    return lines


def charvalue(char: str) -> int:
    values = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    return values.index(char)


def main():
    rucksacks = readinput()

    # part 1
    prios = 0
    for rucksack in rucksacks:
        middle = len(rucksack) // 2
        left = rucksack[middle:]
        right = rucksack[:middle]
        common = set(left) & set(right)
        for char in common:
            prios += charvalue(char)
    print("Rucksacks priorities: %d" % prios)

    # part 2
    prios = 0
    i = 0
    while i <= len(rucksacks) - 3:
        common = set(rucksacks[i]) & set(rucksacks[i + 1]) & set(rucksacks[i + 2])
        for char in common:
            prios += charvalue(char)
        i += 3
    print("Group rucksacks priorities: %d" % prios)


if __name__ == "__main__":
    main()