from lib import LETTERS_UPPER


def part_1(data):
    deps = {c: [] for c in LETTERS_UPPER}
    for line in data.splitlines():
        fields = line.split()
        a, b = fields[1], fields[7]
        deps[b].append(a)
    ready = []
    for x, ys in deps.items():
        if len(ys) == 0:
            ready.append(x)
    seq = []
    ready = sorted(ready)
    while ready:
        current, ready = ready[0], ready[1:]
        seq.append(current)
        for x, ys in deps.items():
            if current in ys:
                ys.remove(current)
                if len(ys) == 0:
                    ready.append(x)
                    ready = sorted(ready)

    print("".join(seq))


def score(c):
    return 1 + ord(c) - ord("A") + 60


def part_2(data):
    deps = {c: [] for c in LETTERS_UPPER}
    for line in data.splitlines():
        fields = line.split()
        a, b = fields[1], fields[7]
        deps[b].append(a)

    ready = []
    done = []
    for x, ys in deps.items():
        if len(ys) == 0:
            ready.append(x)
    workers = {}

    steps = 0
    while len(done) != 26:
        ready = sorted(ready)
        while len(ready) > 0 and len(workers) < 5:
            current, ready = ready[0], ready[1:]
            workers[current] = score(current)

        to_del = []
        for k in workers.keys():
            workers[k] -= 1
            if workers[k] == 0:
                to_del.append(k)
                done.append(k)
                for x, ys in deps.items():
                    if k in ys:
                        ys.remove(k)
                        if len(ys) == 0:
                            ready.append(x)
        for k in to_del:
            del workers[k]
        steps += 1
    print(steps)


def main():
    input_file = __file__.replace(".py", ".txt")
    with open(input_file) as f:
        data = f.read()
    part_1(data)
    part_2(data)


if __name__ == "__main__":
    main()