diff --git a/cipher.py b/cipher.py
new file mode 100644
index 0000000..b8495a4
--- /dev/null
+++ b/cipher.py
@@ -0,0 +1,28 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Mon Oct 25 16:36:54 2021
+
+@author: deyasini
+"""
+
+def cipher(map_from, map_to, code):
+    """ map_from, map_to: strings where each contain 
+                          N unique lowercase letters. 
+        code: string (assume it only contains letters also in map_from)
+        Returns a tuple of (key_code, decoded).
+        key_code is a dictionary with N keys mapping str to str where 
+        each key is a letter in map_from at index i and the corresponding 
+        value is the letter in map_to at index i. 
+        decoded is a string that contains the decoded version 
+        of code using the key_code mapping. """
+    key_code={}
+    i=0
+    d=[]
+    for char in map_from:
+        key_code[char]=map_to[i]
+        i+=1
+    
+    for char in code:
+        d.append(key_code[char])
+    decoded=''.join(d)
+    return (key_code, decoded)
\ No newline at end of file
diff --git a/perfect_square.py b/perfect_square.py
new file mode 100644
index 0000000..cee8bd0
--- /dev/null
+++ b/perfect_square.py
@@ -0,0 +1,15 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Sun Sep 26 18:39:44 2021
+
+@author: deyas
+"""
+
+def is_square(n):    
+   ans=0
+   while ans**2<n:
+       ans+=1
+   if ans**2==n:
+       print ("perfect sq")
+   else:
+       print ("not perfect sq")
\ No newline at end of file