#include <bits/stdc++.h>
using namespace std;
int main() {
  float n, p, sum = 0;
  int i;
  double ans;
  cin >> n;
  vector<int> v;
  for (i = 0; i < n; i++) {
    cin >> p;
    v.push_back(p);
  }
  for (i = 0; i < n; i++) sum = sum + v[i];
  ans = sum / n;
  cout << ans;
  return 0;
}
