#include<iostream>
#include<algorithm>
#include<vector>
#include<math.h>

using namespace std;

typedef long long ll;

int main() {

	ll mid = 0;
	ll n = 0;
	vector < ll > data;
	cin >> n;
	for (int i = 0;i < n;i++) {
		int buff;
		cin >> buff;
		data.push_back(buff);
	}

	sort(data.begin(),data.end());
	mid = (data.size() - 1) / 2;
	ll target = data[mid];
	ll distance = 0;
	for (int i : data) {
		if (i != data[mid]) {
			distance += abs(i-data[mid]);
		}
	}

	cout << distance << endl;

	return 0;
}