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

class Codechef
{
    public static String reverse(String input) {
        if(input.equals(""))
            return "";
        return reverse(input.substring(1)) + input.charAt(0);
    }
	public static void main (String[] args) throws java.lang.Exception
	{
	    
	   System.out.println(reverse("hello"));
	}
}