#include <bits/stdc++.h>
using namespace std;
int main(void) {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long N;
  cin >> N;
  vector<long long> vec(N);
  for (long long i = 0; i < N; ++i) cin >> vec[i];
  sort(vec.begin(), vec.end());
  for (auto i : vec) cout << i << " ";
  double ans = double(vec[0] + vec[1]) / 2;
  for (long long i = 2; i < N; ++i) ans = double(ans + vec[i]) / 2;
  cout << fixed << setprecision(15);
  cout << ans << "\n";
}
