#include <iostream>
#include <string>

using namespace std;

int main()
{
    string fruit, day;
    double quantity;

    cin >> fruit >> day >> quantity;

    double price = 0;

    if (day == "Monday" || day == "Tuesday" || day == "Wednesday" || day == "Thursday" || day == "Friday")
    {
        if (fruit == "banana")
            price = 2.50;
        else if (fruit == "apple")
            price = 1.20;
        else if (fruit == "orange")
            price = 0.85;
        else if (fruit == "grapefruit")
            price = 1.45;
        else if (fruit == "kiwi")
            price = 2.70;
        else if (fruit == "pineapple")
            price = 5.50;
        else if (fruit == "grapes")
            price = 3.85;
        else
            cout << "error" << endl;
    }
    else if (day == "Saturday" || day == "Sunday")
    {
        if (fruit == "banana")
            price = 2.70;
        else if (fruit == "apple")
            price = 1.25;
        else if (fruit == "orange")
            price = 0.90;
        else if (fruit == "grapefruit")
            price = 1.60;
        else if (fruit == "kiwi")
            price = 3;
        else if (fruit == "pineapple")
            price = 5.60;
        else if (fruit == "grapes")
            price = 4.20;
        else {
            cout << "error" << endl;
        }
        cout.setf(ios::fixed);
        cout.precision(2);

        cout << price * quantity << endl;


        return 0;
    }
}