#include <stdio.h>

double avg(double * arr,int students)
{

    int i;
    double average=0;

    for(i=0;i<students;i++){
        average=average+(*(arr+i));
    }

    average=average/students;

    int temp=average*100;

    average=temp/100.0;

    return average;
}


double mon(double * arr,int students,double average)
{
    int i;
    double count=0;

    for(i=0;i<students;i++){

        if(*(arr+i)<average){
            double temp=average-*(arr+i);

            int a=temp*100;

            temp=a/100.0;

            count=count+temp;
        }
    }

    return count;
}


int main(void)
{
    // your code goes here
    int students;

    scanf("%d",&students);

    while(students!=0){

        double arr[students];
        int i;

        for(i=0;i<students;i++){
            scanf("%lf",&arr[i]);

        }

        double average=avg(arr,students);

        static double dummy = average;
        //printf("%lf\n",average);

        double money=mon(arr,students,average);

        printf("$%.2lf\n",money);

        scanf("%d",&students);

    }

    return 0;
}