#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int> vec(n);
    for (auto& i : vec) {
        cin >> i;
    }
    sort(vec.begin(), vec.end());
    if (n % 2 == 1) {
        cout << vec.at(n / 2) << endl;
    } else {
        cout << static_cast<double>(vec.at(n / 2) + vec.at(n / 2 - 1)) / 2 <<endl;
    }
    return 0;
}