diff --git a/missing-number/ppxyn1.py b/missing-number/ppxyn1.py
new file mode 100644
index 0000000000..7675528a70
--- /dev/null
+++ b/missing-number/ppxyn1.py
@@ -0,0 +1,12 @@
+# idea : - 
+# Time Complexity : below O(n^2)
+
+class Solution:
+    def missingNumber(self, nums: List[int]) -> int:
+        nums.sort()      
+        for i in range(len(nums)):
+            if nums[i] != i:
+                return i
+        return len(nums)
+    
+