¿How to Load scene without repeating current scene?

Hi, I am developing a game which consists of loading a scene as a mission, when it finishes pressing a button (UI) that loads another random scene but that is not the previous one. I am using this script but I have no results, maybe because I am loading another scene and the script is restarted.

Thanks for your help. This my code but dont work.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.SceneManagement;
using System.Linq;

public class Manager : MonoBehaviour {

	public Button correcto1;

	//public int scoreValue = 1;
	protected const int MAX = 80;
	private List<int> scenes = new List<int>();

	void Start () {

		scenes = new List<int>(Enumerable.Range(1,MAX));
		correcto1.onClick.AddListener (inicfunc);
	}

	void Update () {
		
	}

	void inicfunc()
	{   
		for(int i = 1; i < 80; ++i)
		{
			scenes.Add(i);
		}

		// Get a random index from the list of remaining level 
		int randomIndex = Random.Range(0, scenes.Count);
		int level = scenes[randomIndex];
		scenes.RemoveAt(randomIndex); // Removes the level from the list
		SceneManager.LoadScene(level);
        
		//ScoreManager.score += scoreValue;
		//SceneManager.LoadScene (Random.Range (1,5));
		//SceneManager.LoadScene("ost2");
	}
}

public int ws;

void Start ()


{


ws =Random.Range(0,3);


if(ws == 0)

    {

        StartCoroutine(scene0());

    }

    if(ws == 1)

    {

        StartCoroutine(scene1());

    }

    if(ws == 2)

    {

        StartCoroutine(scene2());

    }

}


IEnumerator scene0()


{

    yield return new WaitForSeconds(0.6f);

   SceneManager.LoadScene("1");

}

IEnumerator scene1()

{

    yield return new WaitForSeconds(0.6f);

   SceneManager.LoadScene("2");

}

IEnumerator scene2()

{

    yield return new WaitForSeconds(0.6f);

   SceneManager.LoadScene("3");

}

//use SceneManagemen