using System;

public class Program
{
    public static void Main()
    {


            var num1 = double.Parse(Console.ReadLine());
            var num2 = double.Parse(Console.ReadLine());
            var num3 = double.Parse(Console.ReadLine());

            if ((num1 == num2)&&(num1==num3)) Console.WriteLine("yes");
            else Console.WriteLine("no");




    }
}