#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>

using namespace std;


int main() {

    int N;
    cin >> N;

    bool isEven = N % 2 == 0;
    vector<double> AS;
    for (int i = 0; i < N; ++i) {
        double A;
        cin >> A;
        AS.push_back(A);
    }

    sort(AS.begin(), AS.end());

    if (N % 2 == 0) {

        double res = (AS[N / 2-1] + AS[N / 2]) / 2.0;

        cout << res << endl;
    } else {
        cout << AS[N / 2] << endl;
    }


    return 0;
}