#include <bits/stdc++.h>
int main(void) {
  int n;
  int a[1000];
  double ans = 0;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    ans += (double)a[i];
  }
  printf("%f\n", ans / (double)n);
}
