diff --git a/11 November Leetcode Challenge 2021/8_uniqueBST.cpp b/11 November Leetcode Challenge 2021/8_uniqueBST.cpp
new file mode 100644
index 0000000..1a14589
--- /dev/null
+++ b/11 November Leetcode Challenge 2021/8_uniqueBST.cpp	
@@ -0,0 +1,9 @@
+class Solution {
+public:
+    int numTrees(int n) {
+        long ans = 1;
+        for(int i = 0; i < n; i++) 
+            ans *= (4*i+2) / (i+2.);
+        return ans;
+    }
+};