#!/usr/bin/env python3

import sys,re
from math import lcm


if __name__ == '__main__':
    lines = [line.strip('\n') for line in open(sys.argv[1])]
    lri = list(lines[0])
    network = {}
    start = []
    for line in lines[2:]:
        groups = re.search(r'(?P<start>.*) = \((?P<left>.*), (?P<right>.*)\)',line)
        network[groups['start']] = (groups['left'], groups['right'])
        if groups['start'][2] == 'A': start.append(groups['start'])

    # challenge 1
    s, e = 'AAA', 'ZZZ'
    current = s
    instr = 0
    while current != e:
        i = 0 if lri[instr%len(lri)] == 'L' else 1
        current = network[current][i]
        instr += 1

    res1 = str(instr)
    print(f"challenge 1:\n{res1}\n")

    # challenge 2
    instr = [0] * len(start)
    ends = []
    for i in range(len(start)):
        ends.append([])
    for a,s in enumerate(start):
        current = s
        while True:
            i = 0 if lri[instr[a]%len(lri)] == 'L' else 1
            current = network[current][i]
            instr[a] += 1
            if current[2] == 'Z':
                b = False
                for c,u in ends[a]:
                    if c == current and (instr[a] % u) == 0:
                        b = True
                        break
                if b: break
                ends[a].append((current, instr[a]))

    res2 = str(lcm(*[e[0][1] for e in ends]))
    print(f"challenge 2:\n{res2}\n")