How to change the damage my gun does?

Hello, I would like to know how to change the damage of my gun according to a public int? If anyone can help please comment down bellow here is the gun script.

 using UnityEngine;
 using System.Collections;
 
 
 public class Gun1 : MonoBehaviour
 {
     private const int V = 3;
 
     //Decal
     public GameObject decalHit;
   public float projectileDestroyTimer = 5f;
 
 
 
 
   //Ámmo
   public int maxAmmoTotal = 30; // Max ammo to carry Example: 30
   public int maxAmmoInClipTotal = 5; // Max ammo total to be able to reload Example: 5
   public int curAmmo = 30; // Current reloadable ammo Example: 30
   public int ammoInClip = 8; // Current ammo in clip Example: 5
   private bool isReloading = false;
 
 
 
 
   //Animation
   public string fireAnimation; //Shoot animation
   public string clipEmptyAnim; //Clip empty animation
   public string reloadAnimation; //Reload animation
   public float reloadTime = 1f; // How long it takes to reload
   public Animator reloadAnimations;
   public Animator ClipEmptyAnimations;
 
 
 
 
   //GameObjects
   public GameObject weapon; //Needed for aiming
   public ParticleSystem muzzleflash;
   public Animator FireAnimation;
   public AudioSource GunSounds;
 
 
 
 
   //Raycast
   private RaycastHit rayHit;
   public float shootDistance = 200f;
 
 
 
 
   //Recoil
   private float defaultRecoil = 50f;
   public float recoil = 50f;
   public float recoilAiming = 10f;
 
 
   //Aim
   public Vector3 aimPos = Vector3.zero;
   private Vector3 defaultPos = Vector3.zero;
   public float smoothTime; //How long it takes to get to the aiming position
   private Vector3 dampVelocity;
   private bool aiming = false;
 
 
   //Audio
   private AudioSource audioSource; //Audio source
   public AudioClip fireSound; //Sound when shooting
   public AudioSource clipEmptySound; //Sound when clip is empty
   public AudioSource reloadSound; //Sound when reloading
 
   //Weapon
   public int hitDamage = 13;
   float LastTimeShot;
   public float TimeBetweenShots = 1;
   public float fireRate = 20f;
 
   private float nextTimeToFire = 0f;
 
 
   //Only for testing
   int removedAmmoRecently; //Only for testing
 
 
   void Start()
   {
     defaultPos = weapon.transform.localPosition;
     defaultRecoil = recoil;
     audioSource = GetComponent<AudioSource>();
   }
 
 
   void Update()
   {
     AimDownSight();
 
      if (Input.GetButton("Fire1") && Time.time >=nextTimeToFire)
         {
             nextTimeToFire = Time.time + 1f / fireRate;
             Shoot();
       
     }
     if(Input.GetButtonDown("Fire2") && !isReloading)
     {
       aiming = !aiming;
     }
 
 
     if (Input.GetKeyDown(KeyCode.R) && !isReloading)
     {
       StartCoroutine("Reload");
     }
   }
 
 
   void Shoot()
   {
     if(ammoInClip != 0 && !isReloading)
     {
       PlaySound(fireSound);
       GunSounds.Play();
       muzzleflash.Play();
       PlayAnimation(fireAnimation);
       GetComponent<Animator>().Play("FireAnimation");
       ammoInClip--;
       Ray ray = Camera.main.ScreenPointToRay(new Vector3(Screen.width/2f + Random.Range(-recoil, recoil), Screen.height/2f + Random.Range(-recoil, recoil), 0f));
       if (Physics.Raycast(ray, out rayHit, shootDistance))
       {
         GameObject decalClone = (GameObject)Instantiate(decalHit, rayHit.point, Quaternion.LookRotation(rayHit.normal, Vector3.forward));
         Destroy(decalClone, projectileDestroyTimer);
 
         DoDamage(rayHit);
       }
     }
     else{
       clipEmptySound.Play();
       GetComponent<Animator>().Play("ClipEmptyAnimation");
     }
     Debug.Log("Ammo: " + ammoInClip + "/" + curAmmo);
   }
 
 
   void DoDamage(RaycastHit hit)
   {
     if(hit.transform.tag == "Enemy")
     {
       if(hit.transform.GetComponent<EnemyHealth>()) //You can change EnemyHealth, to the name of the script that contains the health of the enemy
       {
         hit.transform.SendMessage("ApplyDamage", hitDamage, SendMessageOptions.DontRequireReceiver);
       }
       Debug.Log(hit.transform.name + " has been hit");
     }
   }
 
 
   IEnumerator Reload()
   {
     //If ammoInClip example 5 is equal or greater than  0 and ammoInClip(5) is lower than maxAmmoInClipTotal(The max amount of ammo that can be in a clip) and curAmmo(how much ammo you have like 5/30) is greater than 0
     if (ammoInClip >= 0 && ammoInClip < maxAmmoInClipTotal && curAmmo > 0)
     {
       isReloading = true;
       reloadSound.Play();
       GetComponent<Animator>().Play("reloadAnimations");
       yield return new WaitForSeconds(reloadTime);
       removedAmmoRecently = 0; //You can remove this line, it's only for testing.
       for (int i = 0; i < maxAmmoInClipTotal; i++)
       {
         if (ammoInClip == maxAmmoInClipTotal || curAmmo <= 0)
         {
           break;
         }
         else
         {
           ammoInClip++;
           curAmmo--;
           removedAmmoRecently++; //You can remove this line, it's only for testing. | To check how much ammo has been removed
         }
       }
       isReloading = false;
       Debug.Log("Removed " + removedAmmoRecently + " " + "ammo from pocket ammo. Ammo: " + ammoInClip + "/" + curAmmo); //You can remove this line, it's only for testing. | Prints out how much ammo that has been removed, ammo you have in clip, and how much ammo that is left
     }
     else
     {
       yield break;
     }
   }
 
 
   void PlayAnimation(string anim)
   {
     if (anim != "")
     {
       weapon.GetComponent<Animation>().Play(anim);
     }
   }
 
 
   void PlaySound(AudioClip clip)
   {
     if (clip != null)
     {
       audioSource.PlayOneShot(clip);
     }
   }
 
 
   void AimDownSight()
   {
     if(aiming && weapon.transform.localPosition.normalized != aimPos.normalized)
     {
       weapon.transform.localPosition = Vector3.SmoothDamp (weapon.transform.localPosition, aimPos, ref dampVelocity, smoothTime);
       Debug.Log ("Aiming");
       recoil = recoilAiming;
     }
 
 
     if(!aiming && weapon.transform.localPosition.normalized != defaultPos.normalized)
     {
       weapon.transform.localPosition = Vector3.SmoothDamp (weapon.transform.localPosition, defaultPos, ref dampVelocity, smoothTime);
       Debug.Log ("UnAiming");
       recoil = defaultRecoil;
     }
   }
 
 
   void OnGUI()
   {
     GUILayout.Label("Ammo: " + ammoInClip + "/" + curAmmo);
   }
 }