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

using namespace std;

int main() {
    int n;
    vector<int> v;
    
    cin >> n ;
    
    int tmp;
    for (int i = 0; i < n; i++) {
        cin >> tmp;
        v.push_back(tmp);
    }
    sort(v.begin(), v.end());
    
    int i;
    double ans;
    if (n % 2 == 0) {
        i = (n / 2) - 1;
        ans = (v[i] + v[i + 1]) / 2.0;
    } else {
        i = n / 2;
        ans = v[i];
    }
    
    cout << ans << endl;
    
    return 0;
}