package USD_BG;

import java.util.Scanner;

public class Main {

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

        double legit = Double.parseDouble(scanner.nextLine());
        double wide = Double.parseDouble(scanner.nextLine());
        double tall = Double.parseDouble(scanner.nextLine());
        double percentage = Double.parseDouble(scanner.nextLine());

        double capacity = legit * wide * tall;
        double capacityInMeters = capacity * 0.001;
        double stuffSize = capacityInMeters * (percentage/100.0);
        double freeSpace = capacityInMeters - stuffSize;
        System.out.printf("%.2f", freeSpace);




        }




    }