import java.util.Scanner;
//import java.util.SplittableRandom;

public class Demoo1 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        String product = scanner.nextLine().toLowerCase();
        String city = scanner.nextLine().toLowerCase();
        double number = Double.parseDouble(scanner.nextLine());
        double count = 0;

        if (city.equals("Sofia")) {
            if (product.equals("coffee")) {
                count = number * 0.50;
            } else if (product.equals("water")) {
                count = number * 0.80;
            } else if (product.equals("beer")) {
                count = number * 1.20;
            } else if (product.equals("sweets")) {
                count = number * 1.45;
            } else if (product.equals("peanuts")) {
                count = number * 1.60;
            }
            System.out.println(count);
        }

        else if (city.equals("Plovdiv")) {
            if (product.equals("coffee")) {
                count = 0.40;
            } else if (product.equals("water")) {
                count = 0.70;
            } else if (product.equals("beer")) {
                count = 1.20;
            } else if (product.equals("sweets")) {
                count = 1.30;
            } else if (product.equals("peanuts")) {
                count = 1.50;
            }
            System.out.println(number * count);
        }
       else if (city.equals("Varna") && product.equals("coffee")) {
                count = 0.45;
                double result = number * count;
            System.out.println(result);
            } else if (product.equals("water") && city.equals("Varna")) {
                count = 0.70;
                double result = number * count;
            System.out.println(result);
            } else if (product.equals("beer") && city.equals("Varna")) {
                count = 1.10;
                double result = number * count;
            System.out.println(result);
            } else if (product.equals("sweets") && city.equals("Varna")) {
                count = 1.35;
                double result = number * count;
            System.out.println(result);
            } else if (product.equals("peanuts") && city.equals("Varna")) {
                count = 1.55;
                double result = number * count;
            System.out.println(result);
            }
        }

       // double result = count * number;
       // System.out.println(result);

    }