#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  double v[n];
  for (int i = 0; i < n; ++i) cin >> v[i];
  sort(v, v + n);
  if (n & 1)
    cout << v[n / 2];
  else
    cout << (v[n / 2 - 1] + v[n / 2]) / 2;
}
