How do I add movement for the A to go left, S to go down and D to go right. It needs to use the vectors to do this.

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

public class NewBehaviourScript : MonoBehaviour

$\{$

const float speed $=1\mathrm{.}0$f;

Vector$3$ velocity;

$//$ Start is called before the first frame update

void Start$()$

$\{$

velocity $=$ speed $*$ new Vector$3(1\mathrm{.}0$f$,0\mathrm{.}0$f$,0\mathrm{.}0$f$)$;

$\}$

$//$ Update is called once per frame

void Update$()$

$\{$

Debug.Log$("$Hi$")$;

if $($Input$.$GetKey$("$w$"))$

$\{$

velocity $=$ new Vector$3($velocity$.$x$,-1*$ velocity.y$)$;

$\}$

transform.position $=$ transform.position $+($velocity $*$ Time.deltaTime$)$;

$\}$

$\}$