/* http://es.stackoverflow.com/q/48956/127 */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	private static String invertirPalabra(String palabra) {
	    String res = "";
 
	    if(palabra.length() == 0){
	        res = palabra;
	    }else{
	        res = invertirPalabra(palabra.substring(1)) + palabra.charAt(0);
	    }
	    return res;
	}
 
	public static void main (String[] args) throws java.lang.Exception
	{
		String palabraInvertida = invertirPalabra("¡Esta es una prueba!");
        System.out.println("Resultado: " + palabraInvertida);
	}
}

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