tracks/csharp/config.json in trackler-2.0.6.14 vs tracks/csharp/config.json in trackler-2.0.6.15

@@ -813,9 +813,18 @@
         "Parsing",
         "Transforming"
       ]
     },
     {
+      "slug": "zipper",
+      "difficulty": 10,
+      "topics": [
+        "Trees",
+        "Recursion",
+        "Searching"
+      ]
+    },
+    {
       "slug": "alphametics",
       "difficulty": 10,
       "topics": [
         "Parsing",
         "Dictionaries"