#include <iostream>
#include <stdio.h>
#include <cmath>
#include <algorithm>
#include <vector>

#define FOR(i, a, b) for (int i = a; i < b; i++)
#define FORN(i, a, b) for (int i = a; i <= b; i++)
#define P(s) cout << s << endl
#define PC(condition, _true, _false) if (condition) _true; else _false;
#define toInt(_char) _char - '0'

using namespace std;
//
// Created by karayuu on 2019-02-26.
//

int main() {
    int n;
    cin >> n;

    vector<int> a(n);
    FOR(i, 0, n) {
        cin >> a[i];
    }

    //ソート
    sort(a.begin(), a.end());

    if (n % 2 == 0) {
        P((a[n / 2 - 1] + a[n / 2]) / 2.0);
    } else {
        P(a[(n - 1) / 2]);
    }
}