#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  int sum = 0;
  int i = 0;
  while (i < n) {
    int x;
    cin >> x;
    sum += x;
    ++i;
  }
  cout << fixed << setprecision(12);
  cout << (long double)sum / n;
  return 0;
}
