#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <string>
#include <vector>
#include <cmath>
#include <set>
#include <map>
using namespace std;
using ll = long long;

int main(void)
{
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; i++)
  {
    cin >> A.at(i);
  }

  for (int i = 1; i < N; i++)
  {
    int temp_itr = i - 1;
    int T = A.at(i);
    while (0 <= temp_itr && T <= A.at(temp_itr))
    {
      A.at(temp_itr + 1) = A.at(temp_itr);
      A.at(temp_itr) = T;
      temp_itr--;
    }
  }
  if (A.size() % 2 == 1)
  {
    cout << A.at(N / 2) << endl;
  }
  else
  {
    int H = N / 2;
    double R = (A.at(H) + A.at(H - 1));
    cout << R / 2 << endl;
    /*
   if (R % 2 == 0)
   {
     cout << R / 2 << endl;
   }
   else
   {
     cout << R / 2 << ".5" << endl;
   }
     */
  }
  return 0;
}