#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <cmath>
#include <climits>
#include <iomanip>
#include <set>
#include <map>
using namespace std;
typedef long long ll;
int main(){
    ll n;
    cin >> n;
    vector<ll> a(n);
    for(int i = 0;i < n;i++)cin >> a[i];
    sort(a.begin(),a.end());
    if(n % 2 == 1){
        cout << a[n / 2] << endl;
    }
    else{
        double res = 0;
        res = (double)(a[n / 2] + a[n / 2 - 1]) / 2;
        cout << res << endl;
    }
}