using System;

public class Program

{

    public static void Main()

    {

        String st = "1111111111111001111011111";

        int maxcount = 0;

        int currentcount = 0;

        foreach(char c in st)

        {

            if(c == '1')

            {

                currentcount++;

                if(currentcount > maxcount)

                {

                    maxcount = currentcount;

                }

            }

            else

            {

                currentcount = 0;

            }

        }

        Console.WriteLine("the Maximum number of consecutive 1's = " + maxcount);

    }

}