Given a string S consisting of lower case English alphabets and an integer K.

You need to form a new string P that follows the following conditions:

Task

Determine the string P that satisfies all the given conditions.

Example

Assumptions

Approach

Function Description

Complete the solve function provided in the editor. This function takes the following 3 parameters and returns the valid string:

Input Format

Note: This is the input format you must use to provide custom input (available above the Compile and Test button).

The first line contains a single integer T denoting the number of test cases.
For each test case:
- The first line contains a single integer N denoting the size of string S.
- The second line contains a single integer K denoting the number of new characters added in string S.
- The third line contains the string S.

Output Format

For each test case in a separate line, output a string P that satisfies all the given conditions.

Constraints

\(1 \le T \le 10 \\ 2 \le N \le 2 * 10^5 \\ 2 \le K \le 2 * 10^5\)

Code snippets (also called starter code/boilerplate code)

This question has code snippets for C, CPP, Java, and Python.