Distance

import java.util.Scanner;

public class dista {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        double speed = Integer.parseInt(sc.nextLine());
        double speed1;
        double speed2;
        double t1 = Integer.parseInt(sc.nextLine());
        double t2 = Integer.parseInt(sc.nextLine());
        double t3 = Integer.parseInt(sc.nextLine());

        double x1;
        double x2;
        double x3;
        double x4;

        x1 = t1 / 60;
        t1 = speed * x1;
//      System.out.println(t1);

        speed1 = speed * 10 / 100;
        speed = speed1 + speed;
        x2 = speed * t2 / 60;
//      System.out.println(x2);

        speed1 = speed * 5 / 100;
        speed = speed - speed1;
        x3 = speed * t3 / 60;
//      System.out.println(x3);

        System.out.printf("%.2f", t1 + x2 + x3);
    }
}