#include <bits/stdc++.h>
int main() {
  const int p = 100;
  int n, a[p];
  double sum = 0;
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) {
    scanf("%d", &a[i]), sum += a[i] * p;
  }
  printf("%f", sum / (n * p));
  return 0;
}
