using System;
class Program
{
    static void Main()
    {
        double num1 = double.Parse(Console.ReadLine());
        double num2 = double.Parse(Console.ReadLine());
        double num3 = double.Parse(Console.ReadLine());
        if ((num1 == num2) && (num2 == num3))
        {
            Console.WriteLine("yes");
        }
        else
        {
            Console.WriteLine("no");
        }
    }
}