#include <bits/stdc++.h>
#define INF 2000000000000000000
#define ll long long
#define pll pair<ll, ll>
using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll N;
  cin >> N;
  vector<ll> A(N);
  for (ll i = 0; i < N; ++i) {
    cin >> A.at(i);
  }
  sort(A.begin(), A.end());
  double ans;
  if (N % 2 == 0) {
    ans = (A.at(N / 2 - 1) + A.at(N / 2)) / 2.0;
  }
  else {
    ans = A.at(N / 2);
  }
  cout << ans << "\n";
}