#include <iostream>

using namespace std;

int main () {


        string product;
        string day;
        double quality;
        double price;
        price = 0.0;
        cin >> product >> day >> quality;
        cout .setf(ios::fixed);
        cout.precision(2);


        if (day == "Monday" || day == "Tuesday" || day == "Wednesday" || day == "Thursday" || day == "Friday")
        {
            if (product == "banana")
            {
               double price = quality * 2.50;
                cout << price << endl;
            }else if (product == "apple")
            {
               double price = quality * 1.20;
                cout << price << endl;
            }else if (product == "orange")
            {
               double price = quality * 0.85;
                cout << price << endl;
            }else if (product == "grapefruit")
            {
               double price = quality * 1.45;
                cout << price << endl;
            }else if (product == "kiwi")
            {
               double price = quality * 2.70;
                cout << price << endl;
            }else if (product == "pineapple")
            {
               double price = quality * 5.50;
                cout << price << endl;
            }else if (product == "grapes")
            {
               double price = quality * 3.85;
                cout << price << endl;
            }else
            {
                cout << "error";
            }

        }

       else  if (day == "Saturday" || day == "Sunday")
        {
            if (product == "banana")
            {
               double price = quality * 2.70;
                cout << price << endl;
            }else if (product == "apple")
            {
               double price = quality * 1.25;
                cout << price << endl;
            }else if (product == "orange")
            {
               double price = quality * 0.90;
                cout << price << endl;
            }else if (product == "grapefruit")
            {
               double price = quality * 1.60;
                cout << price << endl;
            }else if (product == "kiwi")
            {
               double price = quality * 3.00;
                cout << price << endl;
            }else if (product == "pineapple")
            {
               double price = quality * 5.60;
                cout << price << endl;
            }else if (product == "grapes")
            {
               double price = quality * 4.20;
                cout << price << endl;
            }
    } else
       {
         cout << "error";
       }




        return 0;

}