#include <bits/stdc++.h>
int main() {
  unsigned n, p, sum = 0;
  double s;
  scanf("%u", &n);
  for (unsigned i = 0; i < n; i++) {
    scanf("%u", &p);
    sum += p;
  }
  s = (double)sum / n;
  printf("%.12f", s);
  return 0;
}
