#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }

    sort(a.begin(), a.end());
    int m = a[n/2];

    int res = 0;
    for (int i: a) {
        res += abs(i-m);
    }

    cout << res << endl;

    return 0;
}