• Hints on restricted sum

Question related to mission Restricted sum


I've tried a few different things, but a solution I can't seem to get. My attempts mostly involve adding the items in the list data; data = [1, 2, 3] to count, using count += data[:], but I run into all kind of errors, then try to use many different list methods and string functions, but still don't get a solution. Could anyone give me some hints?