{{{~cpp
#include <iostream>
using namespace std;
#include <vector>
#include <numeric>

int num, i, temp1;
double temp_max,temp_min;
vector<double> test;

void process()
{
	cout.setf(ios::fixed, ios::floatfield); 
    cout.setf(ios::showpoint); 
    cout.precision(2);
	double max=0.0, min=0.0;
	num = int(accumulate(test.begin(),test.end(),0.0)/test.size()*1000);
	temp_max = double((num + 10)/10)/100;
	temp_min = double((num)/10)/100;
	if(num % 10 == 0)		
		temp_max = temp_min;

	for(i = 0; i < test.size(); i++)
	{
		if(test[i] > temp_max)
		{
			max += test[i] - temp_max;
		}
		else if( test[i] < temp_min)
		{
			min += temp_min - test[i];
		}
	}
	if(min > max)
		max = min;


	cout << "$" << max << endl;

}

int main()
{
	cin >> num;
	while(num)
	{
		
		for(i = 0; i <num; i++)
		{
			cin >> temp_max;
			test.push_back(temp_max);
		}

		process();
		test.clear();
		cin >> num;
	}

	return 0;
}
}}}