#include <bits/stdc++.h>
using namespace std;
int main() {
  int n = 0;
  int sum = 0;
  cin >> n;
  int temp = 0;
  for (int i = 0; i < n; i++) {
    cin >> temp;
    sum += temp;
  }
  double per = (double)sum / n;
  printf("%0.5f", per);
}
