import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();
        sc.nextLine();

        for(int i=0;i<t;i++){
            int n = sc.nextInt();
            sc.nextLine();
            String s = sc.nextLine();
            if(n >= s.length()){
                String reversed = reverse(s);
                System.out.println(reversed);
            }
        }
        sc.close();
    }
    // 反转String类型的字符串。去掉空格
    private static String reverse(String s){
        // 去掉空格
        String noSpace = s.replaceAll(" ", "");
        StringBuilder sb = new StringBuilder(noSpace);
        return sb.reverse().toString();
    }
}