#include <bits/stdc++.h>
using namespace std;
void read() {
  int n, k, ml;
  float sum = 0;
  cin >> n;
  k = n;
  while (n--) {
    cin >> ml;
    sum = sum + ml;
  }
  cout << sum / k << endl;
  return;
}
int main() {
  read();
  return 0;
}
