#include <iostream>
#include <algorithm>
using namespace std;
const int N = 100010;
int a[N];
int n, res;
int main()
{
    cin >> n;
    for(int i = 0; i < n; ++ i) cin >> a[i];

    sort(a, a + n);
    for(int i = 0; i < n; ++ i) res += abs(a[i] - a[n / 2]);

    cout << res << '\n';
    return 0;
}