#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(0);
  long long n;
  cin >> n;
  long long a[n + 1], tong = 0;
  for (int i = 1; i <= n; i++) cin >> a[i];
  for (int i = 1; i <= n; i++) tong += a[i];
  cout << (float)tong / n;
  return 0;
}
