#include <bits/stdc++.h>
int main() {
  int n, i, a;
  double s = 0.0, d;
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%d", &a);
    s += a;
  }
  d = s / n;
  printf("%.12lf\n", d);
  return 0;
}
