#include <iostream>
#include <string>


using namespace std;

int main() {

	string fruit, dayOfWeek;
	double quantity, price;
	cin >> fruit >> dayOfWeek >> quantity;

	price = 0;
	cout.setf(ios::fixed);
	cout.precision(2);

	if (dayOfWeek == "Monday" || dayOfWeek == "Tuesday" || dayOfWeek == "Wednesday" || dayOfWeek == "Thursday" || dayOfWeek == "Friday")
	{
		if (fruit == "banana")
		{
			price = 2.5 * quantity;
			cout << price;
		}
		else if (fruit == "apple")
		{
			price = 1.2 * quantity;
			cout << price;
		}
		else if (fruit == "orange")
		{
			price = 0.85 * quantity;
			cout << price;
		}
		else if (fruit == "grapefruit")
		{
			price = 1.45 * quantity;
			cout << price;
		}
		else if (fruit == "kiwi")
		{
			price = 2.7 * quantity;
			cout << price;
		}
		else if (fruit == "pineapple")
		{
			price = 5.5 * quantity;
			cout << price;
		}
		else if (fruit == "grapes")
		{
			price = 3.85 * quantity;
			cout << price;
		}
		else
		{
			cout << "error" << endl;
		}
	}
	else if (dayOfWeek == "Saturday" || dayOfWeek == "Sunday")
	{
		if (fruit == "banana")
		{
			price = 2.7 * quantity;
			cout << price;
		}
		else if (fruit == "apple")
		{
			price = 1.25 * quantity;
			cout << price;
		}
		else if (fruit == "orange")
		{
			price = 0.90 * quantity;
			cout << price;
		}
		else if (fruit == "grapefruit")
		{
			price = 1.6 * quantity;
			cout << price;
		}
		else if (fruit == "kiwi")
		{
			price = 3 * quantity;;
			cout << price;
		}
		else if (fruit == "pineapple")
		{
			price = 5.6 * quantity;
			cout << price;
		}
		else if (fruit == "grapes")
		{
			price = 4.2 * quantity;
			cout << price;
		}
		else
		{
			cout << "error" << endl;
		}
	}
	else
	{
		cout << "error" << endl;
	}


	//cout.setf(ios::fixed);
	//cout.precision(2);

	//cout << price * quantity << endl;

	return 0;
}