uva10137

#include<stdio.h>
#include<math.h>

const int N = 1010;

double pay[N];

double total_pay(double ave, int n, double sum)
{
    double now_tot = 0.0;
    double now_ave;
    int cnt = 0, i;
    now_ave = (int)(ave * 100) / 100.0;
    for (i = 0; i < n; i++) {
        if ((now_ave + 0.01) < pay[i]) {
            now_tot += pay[i] - (now_ave + 0.01);
            cnt++;
        }
    }
    if (0.01 * cnt > sum - now_ave * n)
        now_tot += now_ave * n + 0.01 * cnt - sum;
    return now_tot;
}

int main()
{
    int n, i;
    double tot, ave;
    scanf("%d", &n);
    while (n != 0) {
        tot = 0;
        for (i = 0; i < n; i++) {
            scanf("%lf", &pay[i]);
            tot += pay[i];
        }
        ave = tot / n;
        printf("$%.2lf\n", total_pay(ave, n, tot));
        scanf("%d", &n);
    }
    return 0;
}