A. Turtle and Good Stringstime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputTurtle thinks a string $$$s$$$ is a good string if there exists a sequence of strings $$$t_1, t_2, \ldots, t_k$$$ ($$$k$$$ is an arbitrary integer) such that: $$$k \ge 2$$$. $$$s = t_1 + t_2 + \ldots + t_k$$$, where $$$+$$$ represents the concatenation operation. For example, $$$\texttt{abc} = \texttt{a} + \texttt{bc}$$$. For all $$$1 \le i < j \le k$$$, the first character of $$$t_i$$$ isn't equal to the last character of $$$t_j$$$. Turtle is given a string $$$s$$$ consisting of lowercase Latin letters. Please tell him whether the string $$$s$$$ is a good string!InputEach test contains multiple test cases. The first line contains the number of test cases $$$t$$$ ($$$1 \le t \le 500$$$). The description of the test cases follows.The first line of each test case contains a single integer $$$n$$$ ($$$2 \le n \le 100$$$) — the length of the string.The second line of each test case contains a string $$$s$$$ of length $$$n$$$, consisting of lowercase Latin letters.OutputFor each test case, output "YES" if the string $$$s$$$ is a good string, and "NO" otherwise.You can output the answer in any case (upper or lower). For example, the strings "yEs", "yes", "Yes", and "YES" will be recognized as positive responses.ExampleInput42aa3aba4abcb12abcabcabcabcOutputNo
nO
Yes
YES
NoteIn the first test case, the sequence of strings $$$\texttt{a}, \texttt{a}$$$ satisfies the condition $$$s = t_1 + t_2 + \ldots + t_k$$$, but the first character of $$$t_1$$$ is equal to the last character of $$$t_2$$$. It can be seen that there doesn't exist any sequence of strings which satisfies all of the conditions, so the answer is "NO".In the third test case, the sequence of strings $$$\texttt{ab}, \texttt{cb}$$$ satisfies all of the conditions.In the fourth test case, the sequence of strings $$$\texttt{abca}, \texttt{bcab}, \texttt{cabc}$$$ satisfies all of the conditions.