#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define int long long
using namespace std;
typedef pair<int, int> P;
const int mod = 1000000007;
const int INF = 1e18;

signed main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    vector<int> a(n);
    rep(i, 0, n) cin >> a[i];
    sort(a.begin(), a.end());
    rep(i, 1, n){
        if(a[i] != a[0]) break;
        if(i == n - 1){
            cout << 1 << endl;
            return 0;
        }
    }
    int l = n / 4;
    int r = n - 1 - n / 4;
    int ans = 0;
    rep(i, 0, n){
        ans += min(abs(a[i] - a[l]), abs(a[i] - a[r]));
    }
    cout << ans << endl;
}