#include <bits/stdc++.h>
using namespace std;

int main() {
    int n;
    cin >> n;
    vector<double> a(n);
    for (int i = 0; i < n; i++) cin >> a[i];
    sort(a.begin(), a.end());
    if (n % 2 == 1)
        cout << a[n / 2] << endl;
    else
        cout << ((a[n / 2] + a[n / 2 - 1]) / 2) << endl;
    return 0;
}