using System;

public class Program

{

    public static void Main()

    {

        int []arr={0,0,1,1,0,0,0,1,0,0,1,1,1,1};

        int max=0,count=0;

        int totallength = arr.Length;

        for(int i=0;i<totallength;i++)

        {

            if(arr[i]==1){

                count++;

                max=Math.Max(max,count);

            }

            else{

                count=0;

            }

        }

            Console.Write(max);

    }

}