using System;

​

public class Program

{

    public static void Main()

    {

        var speedKmH = int.Parse(Console.ReadLine());

        var firstT = int.Parse(Console.ReadLine())/60.0;

        var secT = int.Parse(Console.ReadLine())/60.0;

        var thirdT = int.Parse(Console.ReadLine())/60.0;

        double firstD = speedKmH * firstT;

        var speedUp = (speedKmH * 0.1)+speedKmH; //+10%

        var secD = secT*speedUp;

        var speedDown = speedUp-(speedUp*0.05);//-5%

        var thirdD = speedDown *thirdT;

​

        Console.WriteLine("{0:f2}",thirdD+secD+firstD);

    }

}