import java.util.Scanner;

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

        String city = scanner.nextLine();
        double quantity = Double.parseDouble(scanner.nextLine());

        double percent = 0;
        if ("Sofia".equals(city)){
            if (quantity >= 0 && quantity <= 500){
                percent = 5;
            } else if (quantity > 500 && quantity <= 1000){
                percent = 7;
            } else if(quantity > 1000 && quantity <= 10000){
                percent = 8;
            } else if (quantity > 10000){
                percent = 12;
            }
        } else if ("Varna".equals(city)){
            if (quantity >= 0 && quantity <= 500){
                percent = 4.5;
            } else if (quantity > 500 && quantity <= 1000){
                percent = 7.5;
            } else if(quantity > 1000 && quantity <= 10000){
                percent = 10;
            } else if (quantity > 10000){
                percent = 13;
            }
        } else if ("Plovdiv".equals(city)){
            if (quantity >= 0 && quantity <= 500){
                percent = 5.5;
            } else if (quantity > 500 && quantity <= 1000){
                percent = 8;
            } else if(quantity > 1000 && quantity <= 10000){
                percent = 12;
            } else {
                percent = 14.5;
            }
        }

        if (quantity >= 0 &&
                ("Sofia".equals(city) || "Varna".equals(city) || "Plovdiv".equals(city))) {
            double result = quantity * (percent / 100);
            System.out.printf("%.2f", result);
        } else {
            System.out.println("error");
        }
    }
}