A14790 | ABC

Recently, the students of School 179 have developed a unique algorithm, which takes in a binary string $s$ as input. However, they soon found out that if some substring $t$ of $s$ is a palindrome of length greater than 1, the algorithm will work incorrectly. Can the students somehow reorder the characters of $s$ so that the algorithm will work correctly on the string?

A binary string is a string where each character is either 0 or 1.

A string $a$ is a substring of a string $b$ if $a$ can be obtained from $b$ by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.

A palindrome is a string that reads the same backwards as forwards.

Each test contains multiple test cases. The first line contains the number of test cases $t$ ( $1 \le t \le 100$ ). Description of the test cases follows.

The first line of each test case contains a single integer $n$ ( $1 \le n \le 100$ ) — the length of the string $s$ .

The second line of each test case contains the string $s$ of length $n$ consisting only of the characters 0 and 1.

For each test case, print YES (case-insensitive) if it is possible to reorder the characters of $s$ so that there are no substrings that are a palindrome of length greater than 1, or NO (case-insensitive) otherwise.