#include <bits/stdc++.h>
using namespace std;
using ill = int long long;
#define rep(i, n) for (ill i = 0; i < (n); i++)
#define all(s) s.begin(), s.end()
using inp = pair<int, int>;
using vecb = vector<bool>;
using vecb2 = vector<vecb>;

int main()
{
    int n;
    cin >> n;
    vector<double> a;
    rep(i, n)
    {
        int s;
        cin >> s;
        a.push_back(s);
    }
    sort(all(a));
    if (n % 2 == 1)
    {
        n = n / 2;
        cout << a[n] << endl;
    }
    else
    {
        n = n / 2;
        cout << fixed << setprecision(1);
        cout << (a[n - 1] + a[n]) / 2 << endl;
    }
}