Atilla's Favorite Problem
In order to write a string, Atilla needs to first learn all letters that are contained in the string.Atilla needs to write a message which can be represented as a string $$$s$$$. He asks you what is the minimum alphabet size required so that one can write this message.The alphabet of size $$$x$$$ ($$$1 \leq x \leq 26$$$) contains only the first $$$x$$$ Latin letters. For example an alphabet of size $$$4$$$ contains only the characters $$$\texttt{a}$$$, $$$\texttt{b}$$$, $$$\texttt{c}$$$ and $$$\texttt{d}$$$.
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 $$$\texttt{abcdefghijklmnopqrstuvw}$$$).
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.
For each test case, output a single integer — the minimum alphabet size required to so that Atilla can write his message $$$s$$$.
for g in [*open(0)][2::2]:
    print(ord(sorted(g)[-1]) - 96)
t = int(input())
for _ in range(t):
    n = int(input())
    s = input()
    max_char = max(s)
    max_index = ord(max_char) - ord('a') + 1
    print(max_index)
for x in [*open(0)][2::2]:
    print(ord(max(x)) - 96)