A namespace can only contain types and namespace declarations

Hello,

I'm trying to integrate adbuddiz in my Android app. I've looked at this tutorial that shows how to integrate it:

Part 1: https://www.youtube.com/watch?v=YU8DK9665ms Part 2: https://www.youtube.com/watch?v=WNkz-uKpEXk

In part 2, he puts some lines of code on one of his scripts. I'm using a different script. When I put those lines of code, I get this error:

error CS0116: A namespace can only contain types and namespace declarations

Here is the script:

 using UnityEngine;
 using System.Collections;
 
 public static int AdsCounts =0; 
 public class PlayButtonTween : MonoBehaviour {
 
     // Use this for initialization
     void Start () {
         iTween.ScaleTo (gameObject, iTween.Hash ("scale", new Vector3 (1.06f, 1.06f, 0), "time", 0.5f, "easetype", iTween.EaseType.linear, "looptype", iTween.LoopType.pingPong));
 
         AdsCount += 1;
         
         if (AdsCount > 2) {
             AdBuddizBinding.ShowAd();
             AdsCount=0;
         }
     }
      
 }

 

It tells me the error on the line 4. I'm not really good at coding. If you know how to fix this please tell me. Help Would be appreciated.