Bike_race

import java.util.Scanner;

/**
 * Created by georgi on 27.1.2017 г..
 */
public class Bike_race {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int junior = Integer.parseInt(scanner.nextLine());
        int senior = Integer.parseInt(scanner.nextLine());
        String trace = scanner.nextLine();
        double juniorFee = 0;
        double seniorFee = 0;
        double totalFee = 0;

        switch (trace) {
            case "trail":
                juniorFee = 5.50;
                seniorFee = 7;
                break;
            case "cross-country":
                juniorFee = 8;
                seniorFee = 9.50;
                break;
            case "downhill":
                juniorFee = 12.25;
                seniorFee = 13.75;
                break;
            case "road":
                juniorFee = 20;
                seniorFee = 21.50;
                break;
        }

        totalFee = (junior * juniorFee) + (senior * seniorFee);
        if (trace.equals("cross-country") && junior + senior >= 50){
            totalFee *= 0.75;
        }
        System.out.printf("%.2f", totalFee *= 0.95);

    }
}