#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  float a = 0;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    a += x;
  }
  a /= n;
  cout << a << "\n";
}
