#include <bits/stdc++.h>
using namespace std;
const int INF = 1001001001;
const int mINF = -1001001001;
int main() {
  int n;
  cin >> n;
  int v[n];
  double ans = 0;
  for (int i = 0; i < (n); i++) {
    cin >> v[i];
    ans += v[i];
  }
  ans /= (double)n;
  cout << fixed << setprecision(10) << ans << endl;
  return 0;
}
