diff --git a/kotlin/67-Add-Binary.kt b/kotlin/0067-add-binary.kt
similarity index 100%
rename from kotlin/67-Add-Binary.kt
rename to kotlin/0067-add-binary.kt
diff --git a/kotlin/169-Majority-Element.kt b/kotlin/0169-majority-element.kt
similarity index 100%
rename from kotlin/169-Majority-Element.kt
rename to kotlin/0169-majority-element.kt
diff --git a/kotlin/621-Task-Scheduler.kt b/kotlin/0621-task-scheduler.kt
similarity index 100%
rename from kotlin/621-Task-Scheduler.kt
rename to kotlin/0621-task-scheduler.kt