using System;

namespace ThreeEqualNumbers
{
    class Program
    {
        static void Main(string[] args)
        {
            var numberOne = double.Parse(Console.ReadLine());
            var numberTwo = double.Parse(Console.ReadLine());
            var numbrtThree = double.Parse(Console.ReadLine());


            if (numberOne == numberTwo)
            {
                if (numberOne == numbrtThree)
                {
                    Console.WriteLine("yes");
                }
                else
                {
                    Console.WriteLine("no");
                }
            }
            else
            {
                Console.WriteLine("no");
            }
        }
    }
}