#include <bits/stdc++.h>



using namespace std;

double arr[1020];

int main()

{

//    double P=0,N=0,F,S,T;

    int n,i,j;

    while(cin>>n && n)

    {

        double avg=0;

        for(i=0;i<n;i++)

        {

           

            scanf("%lf",&arr[i]);

            avg += arr[i];

        }

        avg /= n;

        double P = 0, N = 0;

        for( j = 0; j < n; j++)

        {

            double res = (long) ((arr[j] - avg) * 100.0) / 100.0;

            if(res> 0)

             P += res;

            else

             N += res;

        }

        N = -N;

        if(N>P)

        printf("$%.2f\n", N );

        else

        printf("$%.2f\n",P);

    }

    return 0;

}