Static int wont change from another script

i have a quest where you have to go and find a gameobject and press E and then you should be done with that and my int should rise with one and when it hits 4 it should stop the mission. Here is the scripts,

 using UnityEngine;
 using System.Collections;
 
 public class FjellProveTaking : MonoBehaviour {

 public bool FjellProveTatt = false;
 // public bool shitfuckingshit = false;
 public GameObject FjellObject;
 public GameObject PressE;
 public static bool collidercheck = false;


 // Use this for initialization
 void Start () {
     PressE.SetActive(false);
 }
 
 // Update is called once per frame
 void OnTriggerStay (Collider other) {
     if (collidercheck == true && FjellProveTatt == false)
     {
      //   shitfuckingshit = true;
         PressE.SetActive(true);
         if(Input.GetKey(KeyCode.E))
         {
             FjellMaste.Fjellprovercounter += 1;
             FjellObject.SetActive(false);
             FjellProveTatt = true;
             PressE.SetActive(false);
         }
     }
 }
 }



 using UnityEngine;
 using System.Collections;
 
 public class FjellMaste : MonoBehaviour {
     public static int Fjellprovercounter = 0;
     public GameObject Fjellmission;
     public bool Missionfinshed = false;
     public int provercounter = 0;
     // Use this for initialization
     void Start()
     {
         provercounter = Fjellprovercounter;
     }
 // Update is called once per frame
 void Update()
 {

 }

 public void ProveChecker()
 {
     if (Fjellprovercounter == 4)
     {
         Fjellmission.SetActive(false);
         Missionfinshed = true;
     }
 }
 }