import java.util.Scanner;

public class zadacha2 {


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

        String produckt = scanner.nextLine();
        String town = scanner.nextLine().toLowerCase();
        double quantity = Double.parseDouble(scanner.nextLine());
        double result = 0;
        if (town.equalsIgnoreCase("Sofia")) {
            if (produckt.equalsIgnoreCase("coffee")) {
                result = quantity * 0.5;
            } else if (produckt.equalsIgnoreCase("water")) {
                result = quantity * 0.8;
            } else if (produckt.equalsIgnoreCase("beer")) {
                result = quantity * 1.2;
            } else if (produckt.equalsIgnoreCase("sweets")) {
                result = quantity * 1.45;
            } else if (produckt.equalsIgnoreCase("peanuts")) {
                result = quantity * 1.60;
            }
        }
        if (town.equalsIgnoreCase("Plovdiv")) {
                if (produckt.equalsIgnoreCase("coffee")) {
                    result = quantity * 0.4;
                } else if (produckt.equalsIgnoreCase("water")) {
                    result = quantity * 0.7;
                } else if (produckt.equalsIgnoreCase("beer")) {
                    result = quantity * 1.15;
                } else if (produckt.equalsIgnoreCase("sweets")) {
                    result = quantity * 1.3;
                } else if (produckt.equalsIgnoreCase("peanuts")) {
                    result = quantity * 1.5;
                }
        }
        if (town.equalsIgnoreCase("Varna")) {
                    if (produckt.equalsIgnoreCase("coffee")) {
                        result = quantity * 0.45;
                    } else if (produckt.equalsIgnoreCase("water")) {
                        result = quantity * 0.7;
                    } else if (produckt.equalsIgnoreCase("beer")) {
                        result = quantity * 1.1;
                    } else if (produckt.equalsIgnoreCase("sweets")) {
                        result = quantity * 1.35;
                    } else if (produckt.equalsIgnoreCase("peanuts")) {
                        result = quantity * 1.55;
                    }
        }
         System.out.println(result);
    }
}