Getting errors on my chart script

Hello unity! So in my Chartboost script i keep getting errors about “expected semicolon” “Unexpected Token” Etc. I read the documentation and copied everything from there but i do not know why im getting these errors. Here is my script like for example on the first line that says “using Chartboost;” it tells me to put semicolon for whoever knows the reason why. EDIT: Now Im getting a parsing error which i do not know what that means heres the updated script
**EDIT2: I fixed it **

using UnityEngine;
using System.Collections;
using Chartboost;

public class Chart : MonoBehaviour {

	void OnEnable() {
		// Initialize the Chartboost plugin
		
		// Replace these with your own Android app ID and signature from the Chartboost web portal
		CBBinding.init("CB_APP_ID_ANDROID", "CB_APP_SIG_ANDROID");
	}
	
	
	void OnApplicationPause(bool paused) {
		// Manage Chartboost plugin lifecycle
		CBBinding.pause(paused);
	}
	
	void OnDisable() {
		// Shut down the Chartboost plugin
		CBBinding.destroy();
	}
	
	
	
	public void Update() {
		if (Input.GetKeyUp(KeyCode.Escape)) {
			if (CBBinding.onBackPressed())
				return;
			else
				Application.Quit();
		}
	}

stick using XXXXX, outside the class

like this

using UnityEngine;
using System.Collections;

public class GUITest : MonoBehaviour {
            
    void OnGUI () {
       
    }
}