import java.util.Scanner;

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

        String fruit = scan.nextLine();
        String day = scan.nextLine();
        double count = Double.parseDouble(scan.nextLine());
        double price = 0;
        switch (day) {
            case "Monday":
            case "Tuesday":
            case "Wednesday":
            case "Thursday":
            case "Friday":
                if ("banana".equals(fruit)) {
                    price = 2.50;
                } else if ("apple".equals(fruit)) {
                    price = 1.20;
                } else if ("orange".equals(fruit)) {
                    price = 0.85;
                } else if ("grapefruit".equals(fruit)) {
                    price = 1.45;
                } else if ("kiwi".equals(fruit)) {
                    price = 2.70;
                } else if ("pineapple".equals(fruit)) {
                    price = 5.50;
                } else if ("grapes".equals(fruit)) {
                    price = 3.85;
                }
                break;
            case "Saturday":
            case "Sunday":
                if ("banana".equals(fruit)) {
                    price = 2.70;
                } else if ("apple".equals(fruit)) {
                    price = 1.25;
                } else if ("orange".equals(fruit)) {
                    price = 0.90;
                } else if ("grapefruit".equals(fruit)) {
                    price = 1.60;
                } else if ("kiwi".equals(fruit)) {
                    price = 3.00;
                } else if ("pineapple".equals(fruit)) {
                    price = 5.60;
                } else if ("grapes".equals(fruit)) {
                    price = 4.20;
                }
                break;
        }
        // banana / apple / orange / grapefruit / kiwi / pineapple / grapes
        // Monday / Tuesday / Wednesday / Thursday / Friday / Saturday / Sunday
        if ((day.equals("Monday")
                || day.equals("Tuesday")
                || day.equals("Wednesday")
                || day.equals("Thursday")
                || day.equals("Friday")
                || day.equals("Saturday")
                || day.equals("Sunday")) &&
                (fruit.equals("banana")
                        || fruit.equals("apple")
                        || fruit.equals("orange")
                        || fruit.equals("grapefruit")
                        || fruit.equals("kiwi")
                        || fruit.equals("pineapple")
                        || fruit.equals("grapes"))) {
            price = price * count;
            System.out.printf("%.2f", price);
        } else {
            System.out.println("error");
        }
    }
}