using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string test = "1 1000581 5";

        if(Regex.IsMatch(test, @"^\s*([a-zA-Z]+\s*){2}$"))

        {

            Console.WriteLine("yes");

        }

        else

            Console.WriteLine("no");

    }

}