diff --git a/2020/ruby/day_05.rb b/2020/ruby/day_05.rb
index 9ec1fb4..b369b64 100644
--- a/2020/ruby/day_05.rb
+++ b/2020/ruby/day_05.rb
@@ -1,21 +1,6 @@
-id = proc {|r, c| r * 8 + c }
-
 seats = ARGF.read.split("\n")
   .map {|pass| pass.tr("FB", "01").tr("LR", "01") }
   .map {|pass| pass.to_i(2) }
-  .map {|pass|
-    row = pass >> 3
-    col = pass & 0b111
-    [row, col]
-  }
-# p seats.map(&id).max # day 1
+p seats.max # day 1
 
-rows = seats.map(&:first).minmax
-cols = seats.map(&:last).minmax
-all_seats = Range.new(*rows).flat_map {|r|
-  Range.new(*cols).map {|c|
-    [r, c]
-  }
-}
-seat = (all_seats - seats).find {|r,_| !rows.include?(r) }
-p id[*seat]
+p (0b1000..).find {|id| !seats.include?(id) }