1 files changed, 13 insertions, 0 deletions
diff --git a/progs/a397.py b/progs/a397.py
new file mode 100644
index 0000000..34f81a5
--- /dev/null
+++ b/progs/a397.py
@@ -0,0 +1,13 @@
+def find_missing(ar,N): 
+    l = 0
+    r = N - 1
+    while (l <= r):  
+        mid = (l + r) / 2
+        mid= int (mid) 
+        if (ar[mid] != mid + 1 and ar[mid - 1] == mid): 
+            return (mid + 1)  
+        elif (ar[mid] != mid + 1): 
+            r = mid - 1 
+        else: 
+            l = mid + 1
+    return (-1) 
+\ No newline at end of file