diff --git a/days/src/main/kotlin/Day18.kt b/days/src/main/kotlin/Day18.kt
index e442793..338e0e6 100644
--- a/days/src/main/kotlin/Day18.kt
+++ b/days/src/main/kotlin/Day18.kt
@@ -58,7 +58,7 @@ class Day18(@Lines val input: Input<List<String>>) {
                 operands[i + 1] = result
             }
 
-            return operands.last()
+            return operands.peekLast()
         } else {
 
             var i = 0