#include <bits/stdc++.h>
using namespace std;

int main(){
    int n;
    cin >> n;
    vector<int> a(n);
    for(int i = 0; i < n; i++){
        cin >> a.at(i);
    }
    sort(a.begin(), a.end());
    if(n % 2 == 0){
        cout << 1.0 * (a.at(n / 2 - 1) + a.at(n / 2)) / 2 << endl;
    }
    else if(n % 2 == 1){
        cout << a.at(n / 2)  << endl;
    }
}