#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  vector<double> vec(N);
  for (int X = 0; X < N; X++) {
    cin >> vec.at(X);
  }
  sort(vec.begin(), vec.end());
  int M = vec.at(0);
  for (int X = 1; X < N; X++) {
    M += vec.at(X);
    M /= 2;
  }
  cout << M << endl;
}
