#include <bits/stdc++.h>
using namespace std;
bool comp(int x, int y) { return x > y; }
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
void solveA() {
  int n;
  cin >> n;
  int largest, lowest;
  int amazing = 0;
  for (int i = 0; i < n; i++) {
    int temp;
    cin >> temp;
    if (i == 0) {
      largest = temp;
      lowest = temp;
    } else {
      if (temp > largest) {
        amazing++;
        largest = temp;
      }
      if (temp < lowest) {
        amazing++;
        lowest = temp;
      }
    }
  }
  cout << amazing << endl;
}
void solveB() {
  int n;
  cin >> n;
  double ratio = 0;
  for (int i = 0; i < n; i++) {
    int temp;
    cin >> temp;
    ratio += temp;
  }
  ratio = (1.0 * ratio) / n;
  cout << fixed << setprecision(7) << ratio << endl;
}
int main() {
  solveB();
  return 0;
}
