Notepad#

Description:

Input:

The 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.

Output:

For each testcase, print "YES" if you can type string $$$s$$$ in strictly less than $$$n$$$ operations. Otherwise, print "NO".

Sample Input:

6
10
codeforces
8
labacaba
5
uohhh
16
isthissuffixtree
1
x
4
momo

Sample Output:

NO
YES
NO
YES
NO
YES

Note:

In 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.