diff --git a/capitalize_uncapitalize.py b/capitalize_uncapitalize.py
new file mode 100644
index 0000000..015f6ad
--- /dev/null
+++ b/capitalize_uncapitalize.py
@@ -0,0 +1,15 @@
+a = input("Input a string = ")
+for i in range(len(a)):
+    if(ord(a[i]) > 96 and ord(a[i]) < 123):
+        A_ord = ord(a[i]) - 32
+        A_chr = chr(A_ord)
+        print(A_chr, end="")
+    elif ord(a[i]) > 64 and ord(a[i]) < 91 :
+        A_ord = ord(a[i]) + 32
+        A_chr = chr(A_ord)
+        print(A_chr, end="")
+    elif ord(a[i]) == 32:
+        print(" ", end="")
+    else:
+        print("invalid letter!")
+