import java.util.*;
import java.lang.*;
import java.io.*;

// The main method must be in a class named "Main".
class Main {
    public static void main(String[] args) {
        System.out.println("Hello world!");
        String word="kusuma";
        char[] str_arr=word.toCharArray();
        int left=0;
        int right=str_arr.length-1;
        while (left<right) {
            char temp=str_arr[left];
            str_arr[left]=str_arr[right];
            str_arr[right]=temp;
            left++;
            right--;
        }
        String outpit=new String(str_arr);
        System.out.println(outpit);
    }
}