I need help with this C# script

using UnityEngine; using System.Collections;

public class Player : MonoBehaviour {

 public float force;
 private Rigidbody rb;

 // Use this for initialization
 void Start () {
     rb = GetComponent<Rigidbody>();
 }
 
 // Update is called once per frame
 void Update () {
     float h = Input.GetAxis("Horizontal");
     float v = Input.GetAxis("Vertical");

     Vector3 vector = new Vector3(h, 0.5f, v);
     rb.AddForce(vector * force * Time.deltaTime);
 }

} Estoy llevando cursos de Unity online y el instructor puso esas lineas de programacion, las copie igual y me salta el error de que no puede ser añadido, ¿alguien me puede ayudar? I'm taking online courses of Unity, and the instructor put those lines of programming, just copy them and I get an error that can not be added, can anyone help me?