diff --git a/csharp/684-Redundant-Connection.cs b/csharp/684-Redundant-Connection.cs
new file mode 100644
index 000000000..3b9f76173
--- /dev/null
+++ b/csharp/684-Redundant-Connection.cs
@@ -0,0 +1,45 @@
+public class Solution {
+    public int[] FindRedundantConnection(int[][] edges) {
+        var nodes = edges.Length;
+        int[] parent = new int[nodes + 1];
+        int[] rank   = new int[nodes + 1];
+        
+        for(int i = 0; i < nodes; i++) {
+            parent[i] = i;
+            rank[i] = 1;
+        }
+        
+        int findParent (int n) {
+            var p = parent[n];
+            
+            while(p != parent[p]) {
+                parent[p] = parent[parent[p]];
+                p = parent[p];
+            }
+            
+            return p;
+        }
+        bool union(int n1, int n2) {
+            (int p1, int p2) = (findParent(n1), findParent(n2));
+            
+            if(p1 == p2) return false;
+            
+            if(rank[p1] > rank[p2]) {
+                parent[p2] = p1;
+                rank[p1] += rank[p2];
+            } else {
+                parent[p1] = p2;
+                rank[p2] += rank[p1];
+            }
+            
+            return true;
+        }
+        
+        foreach(var edge in edges) {
+            if(union(edge[0], edge[1]) is false) 
+                return edge;
+        }
+        
+        return new int[2];
+    }
+}
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