#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long n;
  cin >> n;
  double A[n];
  double drinks = 0;
  for (long long i = 0; i < n; i++) {
    cin >> A[i];
    drinks += A[i];
  }
  cout << fixed << setprecision(10) << drinks / (double)n;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solve();
}
