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[]Y = new int[N];
		for(int i = 0; i < N; i++) {
			Y[i] = scan.nextInt();
		}
		scan.close();
		Arrays.sort(Y);
		if(N % 2 == 0) {
			int t = (Y[N / 2] + Y[N /2 - 1]) / 2;
			long ans = 0;
			for(int i = 0; i < N; i++) {
				ans += Math.abs(t - Y[i]);
			}
			System.out.println(ans);
		}else {
			long ans = 0;
			int t = Y[N / 2];
			for(int i = 0; i < N; i++) {
				ans += Math.abs(t - Y[i]);
			}
			System.out.println(ans);
		}
	}
}