#include "bits/stdc++.h"
using namespace std;
#define Would
#define you
const int INF = 999999999;
const int MOD = 1e9 + 7;
const double pi = 3.141592653589793238;

int main() {
	long long n, k[100005];
	cin >> n;
	for (int i = 0; i < n; ++i) { cin >> k[i]; }
	sort(k, k + n);
	long long mon = k[n / 2], ans = 0;
	for (int i = 0; i < n; ++i) {
		ans += abs(k[i] - mon);
	}
	cout << ans << endl;
}