#!/usr/bin/env ruby

input = (ARGV.first.nil? ? DATA : ARGF)
  .readlines(chomp: true)
split = input.index("")

gates = input[split+1..]
wires = input.join(" ").scan(/([a-z0-9]{3})/).flatten.uniq.map { [_1, nil] }.to_h
input[...split]
  .map { _1.split(": ") }
  .each { wires[_1] = _2.to_i }


i = 0
until gates.empty?
  if i >= gates.size
    i = 0
  end
  gate = gates[i]
  in1, op, in2, out = gate.scan(/([a-z0-9]{3}) ([A-Z]+) ([a-z0-9]{3}) -> ([a-z0-9]{3})/).first

  if wires[in1].nil? || wires[in2].nil?
    i += 1
    next
  end

  case op
  when "AND"
    wires[out] = wires[in1] & wires[in2]
  when "OR"
    wires[out] = wires[in1] | wires[in2]
  when "XOR"
    wires[out] = wires[in1] ^ wires[in2]
  end

  gates.delete(gate)
end

p wires.select { _1.match?(/^z/) }.sort_by(&:first).map { _1.last.to_s }.reverse.join.to_i(2)

__END__
x00: 1
x01: 0
x02: 1
x03: 1
x04: 0
y00: 1
y01: 1
y02: 1
y03: 1
y04: 1

ntg XOR fgs -> mjb
y02 OR x01 -> tnw
kwq OR kpj -> z05
x00 OR x03 -> fst
tgd XOR rvg -> z01
vdt OR tnw -> bfw
bfw AND frj -> z10
ffh OR nrd -> bqk
y00 AND y03 -> djm
y03 OR y00 -> psh
bqk OR frj -> z08
tnw OR fst -> frj
gnj AND tgd -> z11
bfw XOR mjb -> z00
x03 OR x00 -> vdt
gnj AND wpb -> z02
x04 AND y00 -> kjc
djm OR pbm -> qhw
nrd AND vdt -> hwm
kjc AND fst -> rvg
y04 OR y02 -> fgs
y01 AND x02 -> pbm
ntg OR kjc -> kwq
psh XOR fgs -> tgd
qhw XOR tgd -> z09
pbm OR djm -> kpj
x03 XOR y03 -> ffh
x00 XOR y04 -> ntg
bfw OR bqk -> z06
nrd XOR fgs -> wpb
frj XOR qhw -> z04
bqk OR frj -> z07
y03 OR x01 -> nrd
hwm AND bqk -> z03
tgd XOR rvg -> z12
tnw OR pbm -> gnj