diff --git a/2021/src/main/kotlin/Day13.kt b/2021/src/main/kotlin/Day13.kt
index 2bd03bc..253a901 100644
--- a/2021/src/main/kotlin/Day13.kt
+++ b/2021/src/main/kotlin/Day13.kt
@@ -23,12 +23,7 @@ class Day13 : BaseDay() {
 
     override fun part2(): String {
         val (nums, folds) = input()
-        var all = nums.toSet()
-
-        folds.forEach { (axis, value) ->
-            all = all.fold(axis, value.toInt())
-        }
-
+        val all = folds.fold(nums.toSet()) { all, (axis, value) -> all.fold(axis, value.toInt()) }
         val res = StringBuilder()
         for (y in 0..all.maxOf { it.y }) {
             for (x in 0..all.maxOf { it.x }) {