2D shooter arm rotation phan 3

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class armrotation : MonoBehaviour {

    public Player player;
    public float x;


    public Vector3 fliparm;

    // Use this for initialization
    void Start () {
        x = transform.localScale.x;
        fliparm = transform.localScale;
        player = GetComponentInParent<Player>();
    }

    // Update is called once per frame
    void Update () {

        Vector3 difference = Input.mousePosition - Camera.main.WorldToScreenPoint(transform.position);
        difference.Normalize();

        float rotZ = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;

        if (difference.x >= 0)
        {
            transform.rotation = Quaternion.Euler(0f, 0f, rotZ);
            player.armright = true;
        }

        else
        {
            transform.rotation = Quaternion.Euler(0f, 0f, rotZ+180);
            player.armright = false;
        }


    }
}