#include <bits/stdc++.h>
using namespace std;
int main() {
  double n, sum = 0;
  cin >> n;
  vector<int> a, b;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    a.push_back(x);
  }
  sort(a.begin(), a.end());
  int ans = a[0];
  for (int i = 1; i < n; i++) {
    ans = (ans + a[i]) / 2;
  }
  cout << ans << endl;
}
