Question from the C# - Fundamentals test

What result will be displayed in the console ?

public static class Helper {
    public static void AddOne(int val) {
      val = val + 1;
    } 
} 


public class Program
{	
	public static void Main()
	{
        int val = 0;
        Helper.AddOne(val);
        Console.WriteLine(val);
    }
}