import java.util.Scanner;

public class __FruitShop {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String fruit = scanner.nextLine();
        String dayFromWeek = scanner.nextLine();
        double quantity = Double.parseDouble(scanner.nextLine());
        double productPrice = 0;
        double totalSum = 0;
        if (dayFromWeek.equals("Monday") || dayFromWeek.equals("Tuesday") ||
                dayFromWeek.equals("Wednesday") || dayFromWeek.equals("Thursday") ||
                dayFromWeek.equals("Friday")) {
            switch (fruit) {
                case "banana":
                    productPrice = 2.5;
                    break;
                case "apple":
                    productPrice = 1.2;
                    break;
                case "orange":
                    productPrice = 0.85;
                    break;
                case "grapefruit":
                    productPrice = 1.45;
                    break;
                case "kiwi":
                    productPrice = 2.7;
                    break;
                case "pineapple":
                    productPrice = 5.5;
                    break;
                case "grapes":
                    productPrice = 3.85;
                    break;

            }
            totalSum = productPrice * quantity;
            System.out.printf("%.2f", totalSum);
        }
        if (dayFromWeek.equals("Saturday") || dayFromWeek.equals("Sunday")) {
            switch (fruit) {
                case "banana":
                    productPrice = 2.7;
                    break;
                case "apple":
                    productPrice = 1.25;
                    break;
                case "orange":
                    productPrice = 0.9;
                    break;
                case "grapefruit":
                    productPrice = 1.6;
                    break;
                case "kiwi":
                    productPrice = 3;
                    break;
                case "pineapple":
                    productPrice = 5.6;
                    break;
                case "grapes":
                    productPrice = 4.2;
                    break;
            }
            totalSum = productPrice * quantity;
            System.out.printf("%.2f", totalSum);
        } else {
            System.out.println("error");
        }
    }
}