Counter help

 var notes : int = 3;
 var notesText : GUIText;
 
 function Update () {
     
     notesText.text = "Notes : " + notes;
     
     if(notes == 3) {
         if(Input.GetKey(KeyCode.R)) {
             Destroy(gameObject);

}}

Hello i need help making a script for my game. I am trying to make a script so that when i player picks up a piece of paper it adds it to the inventory. When the player gets 3 they have the ability to set things on fire by pressing a ceratian key. Then their notes go back to zero. Any help would be appreciated and my preference for a language would be javascript, thanks!