import java.util.Scanner;
// 注意類名必須為 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的區(qū)別
/* while (in.hasNextInt()) { // 注意 while 處理多個(gè) case
int a = in.nextInt();
int b = in.nextInt();
System.out.println(a + b);
}*/
int n = in.nextInt();
for (int i = 0; i < n; i++) {
int len = in.nextInt();
in.nextLine();
String s = in.nextLine();
StringBuilder str = new StringBuilder();
for (int j = len - 1; j >= 0; j--) {
if (s.charAt(j) != ' ') {
str.append(s.charAt(j));
}
}
System.out.println(str.toString());
}
}
}