Make Aesthetic String

Given a positive integer (n) and a string (s), your task is to generate an aesthetic string by making all characters identical. Specifically, you should select the first character of (s) and repeat it (n) times to form the new string.

For example, if (n=5) and (s='abcde'), then the output should be (aaaaa).

inputFormat

Input is given from standard input (stdin). The first line contains an integer (T) representing the number of test cases. Each test case consists of two lines: the first line contains an integer (n) and the second line contains a string (s).

outputFormat

For each test case, output the aesthetic string obtained by repeating the first character of (s) (n) times. Print each result on a new line to standard output (stdout).## sample

3
5
abcde
6
abacbd
4
zzzz

aaaaa
aaaaaa
zzzz