백준 2675(문자열 반복)

import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
for (int i = 0; i<n; i++){
int num = sc.nextInt();
String str = sc.next();
for (int j = 0; j < str.length(); j++){
for ( int k = 0; k < num; k++){
System.out.print(str.charAt(j));
}
}
System.out.println();
}
}
}