08. Pet Shop

import java.util.Scanner;

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

        int countDogPacks = Integer.parseInt(scanner.nextLine());
        int countCatPacks = Integer.parseInt(scanner.nextLine());

        double priceDogFood = countDogPacks * 2.50;
        double priceCatFood = countCatPacks * 4;

        double totalPrice = priceCatFood + priceDogFood;

        System.out.println(totalPrice + " lv.");


    }
}