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