import java.util.Scanner;

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

        String product = scanner.nextLine();
        String city = scanner.nextLine();
        double quantity = Double.parseDouble(scanner.nextLine());
        double priceProduct = 0;


        if (city.equals("Sofia")) {
            if (product.equals("coffee")) {
                priceProduct = 0.50 * quantity;
            }
        }
        if (city.equals("Sofia")) {
            if (product.equals("water")) {
                priceProduct = 0.80 * quantity;
            }
        }
        if (city.equals("Sofia")) {
            if (product.equals("beer")) {
                priceProduct = 1.20 * quantity;

            }
        }
        if (city.equals("Sofia")) {
            if (product.equals("sweets")) {
                priceProduct = 1.45 * quantity;
            }
        }
        if (city.equals("Sofia")) {
            if (product.equals("peanuts")) {
                priceProduct = quantity * 1.60;


            }
        } else if (city.equals("Plovdiv")) {
            if (product.equals("coffee")) {
                priceProduct = 0.40 * quantity;
            }
        }
        if (city.equals("Plovdiv")) {
            if (product.equals("water")) {
                priceProduct = 0.70 * quantity;
            }
        }
        if (city.equals("Plovdiv")) {
            if (product.equals("beer")) {
                priceProduct = quantity * 1.15;
            }
        }
        if (city.equals("Plovdiv")) {
            if (product.equals("sweets")) {
                priceProduct = 1.30 * quantity;
            }
        }
        if (city.equals("Plovdiv")) {
            if (product.equals("peanuts")) {
                priceProduct = quantity * 1.50;


            }
        } else if (city.equals("Varna")) {
            if (product.equals("coffee")) {
                priceProduct = quantity * 0.45;
            }
        }
        if (city.equals("Varna")) {
            if (product.equals("water")) {
                priceProduct = quantity * 0.70;
            }
        }
        if (city.equals("Varna")) {
            if (product.equals("beer")) {
                priceProduct = quantity * 1.10;
            }
        }
        if (city.equals("Varna")) {
            if (product.equals("sweets")) {
                priceProduct = quantity * 1.35;
            }
        }
        if (city.equals("Varna")) {
            if (product.equals("peanuts")) {
                priceProduct = quantity * 1.55;


            }


        }
        System.out.printf("%.1f", priceProduct);}}