#include <bits/stdc++.h>
int main() {
  double a, b, c, i;
  scanf("%lf", &a);
  for (i = 1; i <= a; i++) {
    scanf("%lf", &b);
    c = c + (b / 100);
    b = 0;
  }
  printf("%.12lf", (c / a) * 100);
  return 0;
}
