#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());
  double ans = 0;
  if(n % 2) ans = a.at(n/2) * 2;
  else ans = a.at(n/2) + a.at(n/2-1);
  
  cout << ans / 2 << endl;
}