#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ul = unsigned long;
using ull = unsigned long long;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n;
	cin >> n;

	vector<ll> y(n);
	for (int i = 0; i < n; ++i)
		cin >> y[i];

	sort(y.begin(), y.end());

	ll c = n & 1 ? y[n / 2] : (y[n / 2 - 1] + y[n / 2]) / 2;

	ll res{ 0 };
	for (const auto& it : y)
		res += abs(it - c);
	cout << res << "\n";

	return 0;
}