#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  int a[n];
  double sum = 0;
  for (int &x : a) {
    cin >> x;
    sum += x;
  }
  double ans = sum / n;
  printf("%.12f", ans);
  return 0;
}
