diff --git a/src/main/java/com/fishercoder/solutions/_1836.java b/src/main/java/com/fishercoder/solutions/_1836.java
index 378f91c12b..cad77a9213 100644
--- a/src/main/java/com/fishercoder/solutions/_1836.java
+++ b/src/main/java/com/fishercoder/solutions/_1836.java
@@ -14,16 +14,16 @@ public ListNode deleteDuplicatesUnsorted(ListNode head) {
                 map.put(tmp.val, map.getOrDefault(tmp.val, 0) + 1);
                 tmp = tmp.next;
             }
-            ListNode pre = new ListNode(-1);
-            tmp = pre;
+            ListNode prev = new ListNode(-1);
+            prev.next = head;
             while (head != null) {
-                if (map.get(head.val) == 1) {
-                    tmp.next = new ListNode(head.val);
-                    tmp = tmp.next;
+                if (map.get(head.val) > 1) {
+                    map.put(head.val, map.get(head.val) - 1);
+                    prev.next = head.next;
                 }
                 head = head.next;
             }
-            return pre.next;
+            return prev.next;
         }
     }
 }