#include <bits/stdc++.h>
int main(void) {
  double c, b, d = 0;
  int a;
  scanf("%d", &a);
  c = a * 100.0;
  for (; a; a--) {
    scanf("%lf", &b);
    d = d + b;
  }
  printf("%.12f", d / c * 100.0);
  return 0;
}
