using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

            Regex regexUPCCode = new Regex(@"^[1-9]\d{0,12}$");

            if (regexUPCCode.IsMatch("61720184481")) //UPCCODE

            {

                Console.WriteLine("yes");

            }

            else

            {

                Console.WriteLine("no");

            }

    }

}