#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i;
  double sum, x;
  while (~scanf("%d", &n)) {
    sum = 0.0;
    for (i = 1; i <= n; i++) {
      scanf("%lf", &x);
      sum += x;
    }
    printf("%.12lf\n", sum / n);
  }
  return 0;
}
