public class MyClass {
    public static void main(String args[]) {
        int minCabRange = 0;
        int minBusRange = 20;
        int minTrainRange = 100;

        double baseCabTax = 0.70;
        double dayCabTaxPerKm = 0.79;
        double nightCabTaxPerKm = 0.90;

        double busTaxPerKm = 0.09;
        double trainTaxPerKm = 0.06;

        java.util.Scanner scanner = new java.util.Scanner(System.in);
        int kilometers = scanner.nextInt();

        String tariff = scanner.next();

        double smallest = 0.0;

        if (kilometers < 20) {
            if (tariff.equalsIgnoreCase("day")) {
                smallest = baseCabTax + kilometers * dayCabTaxPerKm;
            }
            if (tariff.equalsIgnoreCase("night")) {
                smallest = baseCabTax + kilometers * nightCabTaxPerKm;
            }
        }
        if (kilometers >= 20 && kilometers < 100) {
            smallest = kilometers * busTaxPerKm;
        }

        if (kilometers >= 100) {
            smallest = kilometers * trainTaxPerKm;
        }

        System.out.print(smallest);
    }
}