#include <iostream>
#include <algorithm>
#define int long long
using namespace std;

int n;
int y[100000];

signed main() {
	int i;
	
	cin >> n;
	for (i = 0; i < n; i++) cin >> y[i];
	sort(y, y + n);
	
	int a = y[n / 2];
	int ans = 0;
	for (i = 0; i < n; i++) {
		if (y[i] < a) ans += a - y[i];
		if (y[i] > a) ans += y[i] - a;
	}
	cout << ans << endl;
	return 0;
}