Hey guys, I was solving a problem and then I just sent it to see if it's correct, I am talking about this problem: https://codeforces.com/problemset/problem/253/A and it gives me WA at the first pretest even tho my solution it's correct, https://codeforces.com/contest/253/submission/47515698 it's about this submission, what is that "checker log" saying there?

Can someone tell me what's wrong with my solution on problem C div3 contest 527? I tried to form the string and did it right in all the examples I could think of, and then trying to check if the query it's a suffix or preffix or if it can be both. Submission: https://codeforces.com/contest/1092/submission/47232626