#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rep3(i, l, n) for (int i = l; i < n; ++i)
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)
#define out(a) cout << a << endl
#define SZ(v) (int)v.size()
#define inf (int)(1e9+7)

int main() {
    
    int n; cin >> n;
    
    int a[n];
    rep(i, n) {
        cin >> a[i];
        
    }
    sort(a, a + n);
    
    if (n % 2 == 0) {
        double med;
        med = a[n / 2 - 1] + a[n / 2];
        med /= 2;
        double sum = 0;
        rep(i, n) {
            sum += abs(a[i] - med);
        }
        out(sum);
    } else {
        int med;
        med = a[n / 2];
        ll sum = 0;
        rep(i, n) {
            sum += abs(a[i] - med);
        }
        out(sum);
    }
    
}