Error cs0200, please help i´m novice

Hi,i´m novice in Unity and i learning from internet, now i learning from youtube link text and he is doing well, but for me don´t work specifically this code:

using UnityEngine;

using System.Collections;

[RequireComponent (typeof (CharacterController))] public class PlayerController : MonoBehaviour {

 // Handling
 public float rotationSpeed = 450;
 public float walkSpeed = 5;
 public float runSpeed = 8;
 
 
 // System
 private Quaternion targetRotation;
 
 
 // Components
 
 
 private CharacterController controller;
 
 
 
 void Start () {
     controller = GetComponent<CharacterController>();
     
 }
 void Update () {
     Vector3 input = new Vector3(Input.GetAxisRaw("Horizontal"),0,Input.GetAxisRaw("Vertical"));
     
     if (input != Vector3.zero) {
         targetRotation = Quaternion.LookRotation(input);
         transform.eulerAngles = Vector3.up = Mathf.MoveTowardsAngle(transform.eulerAngles.y,targetRotation.eulerAngles.y,rotationSpeed = Time.deltaTime);
     }
 }

}

and i got this error "Assets/PlayerController.cs(33,57): error CS0200: Property or indexer `UnityEngine.Vector3.up' cannot be assigned to (it is read only)" can you help me please how to fix it, when it is all a right ?, i´m doing a same thing what does he