diff --git a/skilldown.py b/skilldown.py
index fe0705f..ffdfd2d 100755
--- a/skilldown.py
+++ b/skilldown.py
@@ -5,6 +5,10 @@ import wget as wget
 from urllib.request import urlopen
 from urllib.error import HTTPError
 
+sep = input("Are audio and video in the Same or Different files? [S|D]")
+sep = sep.lower()
+if not(sep=='s' or sep=='d'):
+	raise ValueError("The answer should be S or D")
 #video
 i=0
 while True: