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();
            String reversed = reverseString(s);
            System.out.println(reversed);

        }
        sc.close();
    }
    public static String reverseString(String s){
        StringBuilder sb = new StringBuilder(s);
        return sb.reverse().toString();
    }
}