diff --git a/src/commonMain/kotlin/example.kt b/src/commonMain/kotlin/example.kt
index a6d0836..a106a0e 100644
--- a/src/commonMain/kotlin/example.kt
+++ b/src/commonMain/kotlin/example.kt
@@ -1,7 +1,7 @@
 import arrow.analysis.pre
 
 fun problem(numbers: List<Int>): Int =
-  0 // + numbers[0] + numbers[1] // <- problems!
+  0 + numbers[0] + numbers[1] // <- problems!
 
 fun average(numbers: List<Int>): Int {
   pre(!numbers.isEmpty()) { "list is not empty" }