Advent of code 2024 day 17 part 2

def day17_part2(s):
  program = list(map(int, s.split('Program: ')[1].split(',')))
  k1, k2 = (program[i + 1] for i in range(0, len(program), 2) if program[i] == 1)  # 'bst' params.

  def explore(a, values):
    if not values:
      return a
    solutions = (
        explore(a * 8 + b, values[1:])
        for b in range(8)
        if (b ^ k1 ^ k2 ^ ((a * 8 + b) >> (b ^ k1))) & 7 == values[0]
    )
    return min(solutions, default=1 << 62)

  return explore(0, program[::-1])