diff --git a/BAI1/Program.cs b/BAI1/Program.cs
index 3dc36ad..dbb881f 100644
--- a/BAI1/Program.cs
+++ b/BAI1/Program.cs
@@ -15,23 +15,27 @@ namespace BAI
         /// ------------------------------------------------------------
         public static void Opdr1FilterList(List<int> lijst)
         {
-            Dictionary<int, int> occurences = [];
-            foreach (int i in lijst)
+            Dictionary<int, int> positions = [];
+            for (int i = 0; i < lijst.Count; i++)
             {
-                if (occurences.TryGetValue(i, out int value))
+                if (positions.TryGetValue(lijst[i], out _))
                 {
-                    occurences[i] = ++value;
+                    positions[lijst[i]] = -1;
                 }
                 else
                 {
-                    occurences[i] = 1;
+                    positions[lijst[i]] = i;
                 }
             }
-            foreach (int i in occurences.Keys)
+            for (int i = 0; i < lijst.Count;)
             {
-                if (occurences[i] == 1)
+                if (positions[lijst[i]] != -1)
                 {
-                    lijst.Remove(i);
+                    lijst.RemoveAt(i);
+                }
+                else
+                {
+                    i++;
                 }
             }
         }