A15915. LuoTianyi and the Palindrome String

LuoTianyi gives you a palindrome $^{\dagger}$ string $s$ , and she wants you to find out the length of the longest non-empty subsequence $^{\ddagger}$ of $s$ which is not a palindrome string. If there is no such subsequence, output $-1$ instead.

$^{\dagger}$ A palindrome is a string that reads the same backward as forward. For example, strings "z", "aaa", "aba", "abccba" are palindromes, but strings "codeforces", "reality", "ab" are not.

$^{\ddagger}$ A string $a$ is a subsequence of a string $b$ if $a$ can be obtained from $b$ by deletion of several (possibly, zero or all) characters from $b$ . For example, strings "a", "aaa", "bab" are subsequences of string "abaab", but strings "codeforces", "bbb", "h" are not.

Each test consists of multiple test cases. The first line contains a single integer $t$ ( $1 \le t \le 1000$ ) — the number of test cases. The description of test cases follows.

The first and the only line of each test case contains a single string $s$ ( $1 \le |s| \le 50$ ) consisting of lowercase English letters — the string that LuoTianyi gives you. It's guaranteed that $s$ is a palindrome string.

For each test case, output a single integer — the length of the longest non-empty subsequence which is not a palindrome string. If there is no such subsequence, output $-1$ .

In the first test case, "abcaba" is a subsequence of "abacaba" as we can delete the third letter of "abacaba" to get "abcaba", and "abcaba" is not a palindrome string. We can prove that "abcaba" is an example of the longest subsequences of "abacaba" that isn't palindrome, so that the answer is $6$ .

In the second test case, we can only get "a" and "aa", but they are all palindrome strings, so the answer is $-1$ .