import java.util.Arrays;
import java.util.Scanner;

public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int n = scan.nextInt();
int[] A = new int[n];
for(int i = 0;i < n;i) A[i] = scan.nextInt();
Arrays.sort(A);
int mid = (n - 1)/2;
int sum = 0;
for(int i = 0;i < n;i) sum += Math.abs((A[mid] - A[i]));
System.out.println(sum);
}
}