using System;
public class Program
{
public static void Main(string[] args)
var num1 = int.Parse (Console.ReadLine());
var num2 = int.Parse (Console.ReadLine());
var num3 = int.Parse (Console.ReadLine());
if(num1==num2)
if(num2==num3)
Console.WriteLine("yes");
else
Console.WriteLine("no");
}
