Pet Shop

import java.util.Scanner;

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

        int dogCount = Integer.parseInt(scanner.nextLine());
        int otherAnimals = Integer.parseInt(scanner.nextLine());

        double totalSum = dogCount * 2.5 + otherAnimals * 4;
        System.out.println(
                String.format("%.2f lv.",totalSum));

    }
}