#!/usr/bin/env python

import re
import argparse

RE_BOT = re.compile(r'^bot (\d+) gives low to (.*) (\d+) and high to (.*) (\d+)$')
RE_VALUE = re.compile(r'value (\d+) goes to bot (\d+)$')

BOTS = dict()
BOTS_MOVES = []
OUTPUTS = dict()

def load_file(filename):
    with open(filename) as f:
        for line in f:
            yield line.strip()

def check_robot(number):
    if len(BOTS[number]['values']) != 2:
        return
    BOTS[number]['values'] = sorted(BOTS[number]['values'])
    BOTS_MOVES.append(number)

def process_input(line):
    match = RE_BOT.search(line)
    if match:
        bot = int(match.group(1))
        if bot not in BOTS:
            BOTS[bot] = {
                'values': [],
                'low': None,
                'high': None
            }
        BOTS[bot]['low'] = match.group(2)
        BOTS[bot]['low_number'] = int(match.group(3))
        BOTS[bot]['high'] = match.group(4)
        BOTS[bot]['high_number'] = int(match.group(5))
        return

    match = RE_VALUE.search(line)
    if match:
        bot = int(match.group(2))
        if bot not in BOTS:
            BOTS[bot] = {
                'values': [],
                'low': None,
                'high': None
            }
        BOTS[bot]['values'].append(int(match.group(1)))
        check_robot(bot)
        return

    raise Exception("could not parse line: {}".format(line))

def main(args):
    for LINE in load_file(args.input):
        process_input(LINE)

    while len(BOTS_MOVES):
        bot = BOTS_MOVES.pop(0)
        BOT = BOTS[bot]
        if BOT['low'] == 'bot':
            BOTS[BOT['low_number']]['values'].append(BOT['values'][0])
            check_robot(BOT['low_number'])
        if BOTS[bot]['high'] == 'bot':
            BOTS[BOT['high_number']]['values'].append(BOT['values'][1])
            check_robot(BOT['high_number'])
        if BOT['low'] == 'output':
            if BOT['low_number'] not in OUTPUTS:
                OUTPUTS[BOT['low_number']] = []
	    OUTPUTS[BOT['low_number']].append(BOT['values'][0])
        if BOT['high'] == 'output':
            if BOT['high_number'] not in OUTPUTS:
                OUTPUTS[BOT['high_number']] = []
	    OUTPUTS[BOT['high_number']].append(BOT['values'][1])
		
    print(OUTPUTS[0][0]*OUTPUTS[1][0]*OUTPUTS[2][0])

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='AdventOfCode 2016 Day 01')
    parser.add_argument('--input', '-i', action='store',  required=True, help='input file')
    args = parser.parse_args()

    main(args)