How to restart the game

I am looking for a way that I can restart the game with pressing the letter R without closing out of the application in standalone. I only have 1 scene and I have NO Experience. Please help me:D

using UnityEngine.SceneManagement;


SceneManager.LoadScene( SceneManager.GetActiveScene().name );

@doublemax where do you put this line on code?

using UnityEngine;

public class Restart : MonoBehaviour
{

void Start()
{

}

void Update()
    {
        if (Input.GetKeyDown(KeyCode.R))
        {
            Application.LoadLevel(0);
        }
    }
}

Try this!

@doublemax can I ask why this changes the games lighting?