import java.util.*;
import java.math.*;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int size = sc.nextInt();
int res = 0;
int[] arr = new int[size];
for(int i = 0; i < size; i++){
arr[i] = sc.nextInt();
}
Arrays.sort(arr);
for(int i = 0; i < size; i++){
res += Math.abs(arr[i] - arr[size / 2]);
}
System.out.println(res);
}
}