#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
int x4[] = {1, -1, 0, 0};
int y4[] = {0, 0, 1, -1};
int x8[] = {0, 0, +1, -1, -1, +1, -1, +1};
int y8[] = {-1, +1, 0, 0, +1, +1, -1, -1};
int main() {
  int n;
  while (cin >> n) {
    double sum = 0, x;
    for (int i = 0; i < n; i++) {
      cin >> x;
      sum += x;
    }
    n = (double)n;
    cout << fixed << setprecision(10) << sum / n << endl;
  }
  return 0;
}
