Resources.Load() to load a sliced sprite

I have a sliced sprite named Castillo (Spanish word for ‘Castle’). The slices have default names: Castillo_0, Castillo_1, etc.

I need the slices at runtime, so I have made a Resources folder and I have put the sprite ‘Castillo’ in it.

I have a ‘Director’ empty object with this script:

using UnityEngine;
using System.Collections;

public class Prueba : MonoBehaviour {

	// Use this for initialization
	void Start () {
		GameObject prueba = new GameObject ("prueba");
		SpriteRenderer renderer= prueba.AddComponent<SpriteRenderer> ();
		renderer.sprite = Resources.Load<Sprite> ("Tiles/Castillo/Castillo_1");
	}
	
}

The object ‘prueba’ (‘test’ in Spanish) is created, but no sprite is loaded. If I change the argument of the function Resource.Load to "Tiles/Castillo", then Castillo_0 is loaded. But how can other tiles be accessed?

I have solved my own problem, so I answer to myself. This worked for me:

	void Start () {
		GameObject prueba = new GameObject ("prueba");
		SpriteRenderer renderer= prueba.AddComponent<SpriteRenderer> ();
		Object [] sprites;
		sprites = Resources.LoadAll ("Tiles/Castillo");
		renderer.sprite = (Sprite)sprites [3];
	}