using System;

public class Program

{

    public static void Main()

    {

        string s = "0123456789_";

        //

        // These slices are valid:

        //

        Console.WriteLine(s.Slice(0, 1));  // First char

        Console.WriteLine(s.Slice(0, 2));  // First two chars

        Console.WriteLine(s.Slice(1, 2));  // Second char

        Console.WriteLine(s.Slice(8, 11)); // Last three 

    }

}