// editor5
import java.util.*;
interface Billing {
    int calculateTotal();
    void displayBill();
}
abstract class HotelBooking implements Billing {
    protected String day;
    protected int members;
    protected boolean foodIncluded;
    public HotelBooking(String day, int members, boolean foodIncluded) {
        this.day = day.trim();
        this.members = members;
        this.foodIncluded = foodIncluded;
    }
    public boolean isValidDay() {
        return day.matches("(?i)Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday");
    }
    public boolean isValidMembers() {
        return members >= 1;
    }
}
class WeekdayBooking extends HotelBooking {
    public WeekdayBooking(String day, int members, boolean foodIncluded) {
        super(day, members, foodIncluded);
    }
    public int calculateTotal() {
        int rate = 1000 + (foodIncluded ? 500 : 0); // FIXED: 1000 instead of 1500
        return rate * members;
    }
    public void displayBill() {
        System.out.println(calculateTotal());
    }
}
class WeekendBooking extends HotelBooking {
    public WeekendBooking(String day, int members, boolean foodIncluded) {
        super(day, members, foodIncluded);
    }
    public int calculateTotal() {
        int rate = 2000 + (foodIncluded ? 500 : 0);
        return rate * members;
    }
    public void displayBill() {
        Sytem.out.println(calculateTotal());
    }
}
public class HotelBillingSystem {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String day = sc.nextLine().trim();
        String membersInput = sc.nextLine().trim();
        String foodInput = sc.nextLine().trim().toLowerCase();
        int members;
        try {
            members = Integer.parseInt(membersInput);
        } catch (NumberFormatException e) {
            System.out.println("Invalid input");
            return;
        }
        boolean foodIncluded;
        if (foodInput.equals("yes")) {
            foodIncluded = true;
        } else if (foodInput.equals("no")) {
            foodIncluded = false;
        } else {
            System.out.println("Invalid input");
            return;
        }
        HotelBooking booking;
        if (day.equalsIgnoreCase("Saturday") || day.equalsIgnoreCase("Sunday")) {
            booking = new WeekendBooking(day, members, foodIncluded);
        } else {
            booking = new WeekdayBooking(day, members, foodIncluded);
        }
        if (!booking.isValidDay()) {
            System.out.println("Invalid input");
            return;
        }
        if (!booking.isValidMembers()) {
            System.out.println("-1");
            return;
        }
        booking.displayBill();
    }
}