#!/usr/bin/env python3

import sys, re, math


out = []


def output(i):
   out.append(i) 


def instr(opc, op, ra, rb, rc, p):
    cop = op
    if op in [4,5,6]: cop = [ra,rb,rc][op-4]
    if op == 7: cop = 'ERROR'
    if opc == 0: # 'adv' instruction
        ra = math.trunc(ra / 2**cop)
        p += 2
    elif opc == 1: # 'bxl' instruction
        rb = rb ^ op
        p += 2
    elif opc == 2: # 'bst' instruction
        rb = cop % 8
        p += 2
    elif opc == 3: # 'jnz' instruction
        if ra != 0:
            p = op
        else:
            p += 2
    elif opc == 4: # 'bxc' instruction
        rb = rb ^ rc
        p += 2
    elif opc == 5: # 'out' instruction
        output(cop % 8)
        p += 2
    elif opc == 6: # 'bdv' instruction
        rb = math.trunc(ra / 2**cop)
        p += 2
    elif opc == 7: # 'cdv' instruction
        rc = math.trunc(ra / 2**cop)
        p += 2
    return ra, rb, rc, p


def step(lb, ub, i, exp):
    for ra in range(lb, ub):
        if (((ra//8**i)%8) ^ 1 ^ int((ra//8**i) / 2**((ra//8** i%8)^2)) % 8) == exp: yield ra


if __name__ == '__main__':
    ins = open(sys.argv[1]).read()
    g = re.search(r'Register A: (?P<ra>\d+)\nRegister B: (?P<rb>\d+)\nRegister C: (?P<rc>\d+)\n\nProgram: (?P<prog>(\d+,?)*)', ins)
    ra, rb, rc = int(g['ra']), int(g['rb']), int(g['rc'])
    prog = [int(p) for p in g['prog'].split(',')]
    pointer = 0
    while True:
        if pointer >= len(prog): break
        ra, rb, rc, pointer = instr(prog[pointer], prog[pointer+1], ra, rb, rc, pointer)
    
    possible_bounds = [(0,8)]
    for i in range(15,-1,-1):
        exp = prog[i]
        possible_x = []
        for lb, ub in possible_bounds:
            possible_x += [i for i in step(lb, ub, 0, exp)]
        possible_bounds = [(x*8,(x+1)*8) for x in possible_x]
        ra = min(possible_x)
    


    # challenge 1
    res1 = ','.join([str(o) for o in out])
    print(f"challenge 1:\n{res1}\n")

    # challenge 2
    res2 = ra
    print(f"challenge 2 (only works for my input):\n{res2}")