#include <bits/stdc++.h>
int main() {
  int n, t;
  double sum = 0.0, a;
  double p;
  scanf("%d", &n);
  t = n;
  while (n--) {
    scanf("%lf", &a);
    sum += a;
  }
  p = sum / t;
  printf("%.12lf\n", p);
}
