Hello Codeforces!!!

Can Codeforces improve the question 908A? I submited it and had a WA on test 4! I searched it carefully but the I saw that the answer was 11 , not 10 :( . Can Codeforces fix it?

If I have a mistake, leave a comment for me, please.

Update : Now I know why I'm wrong! Thank for your advice! You can post you username in the comment for free contribution!