$(2)$ Find the character that appears most then acipss at poruent same highest frequency, print the one that os smotest in lexicogr$$phical order. takes $2$ parameters and returns a character deroting the animer in the question:

$N.$ Represents the lengith of the sting

S$.$ Represents the string

Input format for custom testing

Note: Use this input format if you are lestring maing cusem reut of writing code in a language where we dont prowide tolechiat coste

The first line contains T$,$ which represents sec cumber of rest cases.

For each test case

The first line contains an integet $N$

The second the connlains

give code in java the sting $s$

Output format