#include <bits/stdc++.h>
using namespace std;
#define repeat(i,n) for (int i = 0; (i) < (n); ++ (i))

int main() {
    int n; cin >> n;
    vector<int> a(n); repeat(i, n) cin >> a[i];
    sort(a.begin(), a.end());

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