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

int main()
{
  int n;
  cin >> n;

  vector<int> v(n);
  for (int i = 0; i < n; ++i) cin >> v[i];

  int indx = v.size();
  
  sort(v.begin(), v.end());

  if (indx % 2 == 1) cout << v[(indx-1)/2];
  else {
    double tmp = (v[(indx-1)/2] + v[indx/2]) / 2.0;
    cout << tmp << "\n";
  }

  return 0;
  
}