Description

Input

The first line contains a single integer $t$ ($1 \leq t \leq 1000$) — the number of test cases.

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

The second line of each test case contains a string $s$ of length $n$, consisting of lowercase Latin letters.

Output

For each test case, output a single integer — the minimum alphabet size required to so that Atilla can write his message $s$.

5
1
a
4
down
10
codeforces
3
bcf
5
zzzzz
 
 
 
 
 
 

1
23
19
6
26

Note

For the first test case, Atilla needs to know only the character $\texttt{a}$, so the alphabet of size $1$ which only contains $\texttt{a}$ is enough.

For the second test case, Atilla needs to know the characters $\texttt{d}$, $\texttt{o}$, $\texttt{w}$, $\texttt{n}$. The smallest alphabet size that contains all of them is $23$ (such alphabet can be represented as the string $\texttt{abcdefghijklmnopqrstuvw}$).