#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
    int n; cin >> n;
    vector<double> a(n);
    for (int i = 0; i < n; ++i) {
        cin >> a.at(i);
    }
    sort(a.begin(), a.end());
    if (n % 2 == 0) {
        cout << (a.at(n / 2 - 1) + a.at(n / 2)) / 2 << endl;
    }
    else {
        cout << a.at(n / 2) << endl;
    }
}