diff --git a/2021/src/main/kotlin/Day04.kt b/2021/src/main/kotlin/Day04.kt
index 80b247f..95bd1b9 100644
--- a/2021/src/main/kotlin/Day04.kt
+++ b/2021/src/main/kotlin/Day04.kt
@@ -25,26 +25,12 @@ class Day04 : BaseDay() {
     private fun playBoard(board: List<List<Int>>, numbers: List<Int>): Pair<Int, Int> {
         for (round in numbers.indices) {
             val usedNumbers = numbers.take(round)
-            var winning = false
-            for (line in board) {
+            for (line in board + board[0].indices.map { col -> board.map { it[col] } }) {
                 if (usedNumbers.containsAll(line)) {
-                    winning = true
-                    break
+                    val unmarkedNumbers = board.flatten().toMutableSet().also { it.removeAll(usedNumbers) }
+                    return round to unmarkedNumbers.sum() * usedNumbers.last()
                 }
             }
-            if (!winning) {
-                for (i in board[0].indices) {
-                    val column = board.map { it[i] }
-                    if (usedNumbers.containsAll(column)) {
-                        winning = true
-                        break
-                    }
-                }
-            }
-            if (winning) {
-                val unmarkedNumbers = board.flatten().toMutableSet().also { it.removeAll(usedNumbers) }
-                return round to unmarkedNumbers.sum() * usedNumbers.last()
-            }
         }
         error("No wins")
     }