using System;

using System.Text.RegularExpressions;

​

public class Program

{

    public static void Main()

    {

        Regex rgx = new Regex("1");

        var count = 0;

        for (int i = 1; i < 1000000; i++)

        {

            count += rgx.Matches(i.ToString()).Count;

        }

​

        Console.WriteLine(count);

    }

}