zelborsa

package yoyo;

import java.util.Scanner;

public class zelborsa {



    public static void main(String[] args){

        Scanner scan = new Scanner(System.in);
      //cena
        double vegPrice = Double.parseDouble(scan.nextLine());
        double fruitsPrice = Double.parseDouble(scan.nextLine());
      //kg
        int vegPerKg = Integer.parseInt(scan.nextLine());
        int fruitsPerKg = Integer.parseInt(scan.nextLine());
      //kraina cena
        double vegTotal = vegPrice * vegPerKg;
        double fruitTotal = fruitsPrice * fruitsPerKg;

        System.out.println((fruitTotal + vegTotal) / 1.94);
      }
}