#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;
}