Why do i get a null reference exception here?

help
1

using System;

public class Test
{
public static void Main()
{
var input = Console.ReadLine();
var updatedArray = input.Split(’ ');
var a = Convert.ToInt32(updatedArray[0]);
var b = Convert.ToInt32(updatedArray[1]);
var x = Convert.ToInt32(updatedArray[2]);
var y = Convert.ToInt32(updatedArray[3]);
Console.WriteLine(ax + by);
}
}

2

Are you trying to run without providing custom input?