unity3d - pass int value from one script to another script in unity -

i'm trying pass public int score value 1 script script giving me error an object reference required access non-static member , here have done

public class firearrow : monobehaviour {     public gameobject arrow;     public gameobject apple;     public int score = 0;       // use initialization     void start () {         this.gameobject.getcomponent<rigidbody2d> ().addforce (transform.right*1500.0f);      }       // update called once per frame     void update () {         vector3 diff = camera.main.screentoworldpoint(input.mouseposition) - transform.position;         diff.normalize();          float rot_z = mathf.atan2(diff.y, diff.x) * mathf.rad2deg;         transform.rotation = quaternion.euler(0f, 0f, rot_z - 0);          if (input.getmousebuttonup (0)) {               gameobject bullet_new;              bullet_new = instantiate (arrow,new vector2 (-0.23f, -3.78f), quaternion.identity) gameobject;             raycasthit2d hit = physics2d.raycast(camera.main.screentoworldpoint(input.mouseposition),vector2.zero);             if (hit.collider!= null ) {                  leantween.move(bullet_new,  hit.collider.transform.localposition, 1);                 if(hit.collider.tag == "fruit")                 {                                score++;                     destroy(hit.collider.gameobject,1);                     destroy(bullet_new,1);                 }              }           }     }     } 

the class want access score

public class tick : monobehaviour {     public text wintext;     // use initialization     void start () {         wintext.text = "";     }      // update called once per frame     void update () {          if (input.getmousebuttonup (0)) {             if(firearrow.score == 3)             {                 wintext.text="you win";              }              }      }        } 

any suggestions?

change line

public int score = 0; 

to

public static int score = 0; 

note must have 1 single instance of class firearrow, otherwise might run concurrency issues.