стало писать ошибку 1061

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

public class healyhpoint : MonoBehaviour
{
    public int hp;
    public Text hpT;
    public int hpDamage;

    void Start()
    {
        hpT.text = hp.ToString();
    }

    private void OnCollisionEnter2D(Collision2D collision)
    {
        if (collision.GameObjectTag == ("thorn"))
        {
            hp = hp - hpDamage;
            hpT.text = hp.ToString();
        }
    }
}