String Reformat

You are given a string ‘S’ consisting of alphanumeric characters, the string divided into groups by a ‘-’. Your task is to reformat the string that all the groups contain exactly ‘K’ characters. All the lowercase characters should be converted to uppercase.

Note:

The first group may have fewer characters than ‘K’.

For example:

You are given ‘S’ =’A1-ijklmno-pqr’ and k = ‘3’, then the string contains 3 parts, [“A1”, “ijklmno”, “pqr”], then you can form the string in groups ["A1I”, “JKL”, “MNO”, “PQR"] of uppercase characters. Hence the answer is "A1I-JKL-MNO-PQR"

Input Format:

 The first line of input contains the integer ‘T’ representing the number of test cases.

The first line of each test case contains one integer ‘K’, representing the size of the group the string is to be divided.

The second line of each test case contains the string ‘S’ representing the given string.

Output Format:

For each test case, print a single string consisting of alphanumeric characters divided into groups of size ‘K’ separated by ‘-’.

Print a separate line for each test case.

Constraints:

1 <= T <= 10
1 <= K <= 10^8
1 <= |S| <= 10^8

All characters in ‘S’ are alphanumeric and ‘-’.

Time Limit: 1 sec

Note:

You do not need to print anything. It has already been taken care of. Just implement the function.