B. Notepad#time limit per test3 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputYou want to type the string s, consisting of n lowercase Latin letters, using your favorite text editor Notepad#.Notepad# supports two kinds of operations:   append any letter to the end of the string;  copy a continuous substring of an already typed string and paste this substring to the end of the string. Can you type string s in strictly less than n operations?InputThe first line contains a single integer t (1 \le t \le 10^4) — the number of testcases.The first line of each testcase contains a single integer n (1 \le n \le 2 \cdot 10^5) — the length of the string s.The second line contains a string s, consisting of n lowercase Latin letters.The sum of n doesn't exceed 2 \cdot 10^5 over all testcases.OutputFor each testcase, print "YES" if you can type string s in strictly less than n operations. Otherwise, print "NO".ExampleInput
610codeforces8labacaba5uohhh16isthissuffixtree1x4momoOutput
NO
YES
NO
YES
NO
YES
NoteIn the first testcase, you can start with typing "codef" (5 operations), then copy "o" (1 operation) from an already typed part, then finish with typing "rces" (4 operations). That will be 10 operations, which is not strictly less than n. There exist other ways to type "codeforces". However, no matter what you do, you can't do less than n operations.In the second testcase, you can type "labac" (5 operations), then copy "aba" (1 operation), finishing the string in 6 operations.
610codeforces8labacaba5uohhh16isthissuffixtree1x4momo
NO YES NO YES NO YES 
['implementation', '*1000']