#include <bits/stdc++.h>
using namespace std;
void solve() {
  int n;
  cin >> n;
  int o = n;
  float ans = 0.0;
  while (n--) {
    int a;
    cin >> a;
    ans += (float)a / o;
  }
  cout << ans << endl;
}
int main() { solve(); }
