#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a[100];
  cin >> n;
  for (int i = 0; i < n; i++) cin >> a[i];
  int i = 0;
  float sum = 0;
  cout.precision(12);
  cout.setf(ios::showpoint);
  for (i = 0; i < n; i++) {
    if (a[i] != 0) {
      sum += (float)a[i] / 100;
    }
  }
  float t = float((sum / n) * 100);
  cout << t;
}
