#include <iostream>
#include <cmath>


using namespace std;

int main() {

	string city;
	double sales;
	cin >> city >> sales;

	double commission = -1;

	if (city == "Sofia")
	{
		if		(sales >= 0		&& sales <= 500)	commission = sales * 0.05;
		else if (sales > 500	&& sales <= 1000)	commission = sales * 0.07;
		else if (sales > 1000	&& sales <= 10000)	commission = sales * 0.08;
		else if (sales > 10000)						commission = sales * 0.12;
	}
	else if (city == "Varna")
	{
		if		(sales >= 0		&& sales <= 500)	commission = sales * 0.045;
		else if (sales > 500	&& sales <= 1000)	commission = sales * 0.075;
		else if (sales > 1000	&& sales <= 10000)	commission = sales * 0.1;
		else if (sales > 10000)						commission = sales * 0.13;


	}
	else if (city == "Plovdiv")
	{
		if		(sales >= 0		&& sales <= 500)	commission = sales * 0.055;
		else if (sales > 500	&& sales <= 1000)	commission = sales * 0.08;
		else if (sales > 1000	&& sales <= 10000)	commission = sales * 0.12;
		else if (sales > 10000)						commission = sales * 0.145;
	}

	//if (sales > 0)
	//{
	//	cout.setf(ios::fixed);
	//	cout.precision(2);
	//	cout << commission << endl;
	//}
	//else
	//{
	//	cout << "error" << endl;
//	}
	if (commission < 0)
	{
		cout << "error";
	}
	else
	{
	cout.setf(ios::fixed);
	cout.precision(2);
	cout << commission << endl;
	}

	return 0;
}