#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, i, t1, t = 0, b[105];
  double sum = 0;
  cin >> a;
  for (i = 0; i < a; i++) {
    cin >> b[i];
    sum += b[i];
  }
  sum /= a;
  printf("%.12f\n", sum);
  return 0;
}
