diff --git a/24/main.rb b/24/main.rb
old mode 100755
new mode 100644
index dfb703a..953b212
--- a/24/main.rb
+++ b/24/main.rb
@@ -36,58 +36,44 @@ until gates.empty?
   gates.delete(gate)
 end
 
-p wires.select { _1.match?(/^x/) }.sort_by(&:first).map { _1.last.to_s }.reverse.join.to_i(2)
-p wires.select { _1.match?(/^y/) }.sort_by(&:first).map { _1.last.to_s }.reverse.join.to_i(2)
-x = wires.select { _1.match?(/^x/) }.sort_by(&:first).map { _1.last.to_s }.reverse.join.to_i(2)
-y = wires.select { _1.match?(/^y/) }.sort_by(&:first).map { _1.last.to_s }.reverse.join.to_i(2)
-p (x + y)
-p wires.select { _1.match?(/^z/) }.sort_by(&:first).map { _1.last.to_s }.reverse.join.to_i(2)
+x = wires.select { _1.match?(/^x/) }.sort_by(&:first).map { _1.last.to_s }.reverse.join
+xi = x.to_i(2)
+y = wires.select { _1.match?(/^y/) }.sort_by(&:first).map { _1.last.to_s }.reverse.join
+yi = y.to_i(2)
+z = wires.select { _1.match?(/^z/) }.sort_by(&:first).map { _1.last.to_s }.reverse.join
+zi = z.to_i(2)
+
+gates = input[split+1..]
+(x.size - 1).downto(0).each do |i|
+  if x[i].to_i ^ y[i].to_i != z[i + 1].to_i
+    p " " + x
+    p " " + y
+    p z
+    p (" " * (i + 1)) + "^"
+    # require"debug";debugger
+    puts "Failed XOR at #{i}: #{gates.select { _1.match?(/z#{'%02d' % i}/) }}"
+    break
+  end
+end
 
 __END__
-x00: 1
-x01: 0
-x02: 1
+x00: 0
+x01: 1
+x02: 0
 x03: 1
 x04: 0
-y00: 1
-y01: 1
+x05: 1
+y00: 0
+y01: 0
 y02: 1
 y03: 1
-y04: 1
+y04: 0
+y05: 1
+
+x00 AND y00 -> z05
+x01 AND y01 -> z02
+x02 AND y02 -> z01
+x03 AND y03 -> z03
+x04 AND y04 -> z04
+x05 AND y05 -> z00
 
-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