#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

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