
int main() {
  double t = 2.0, sum[128] = {0};
  int i;
  sum[1] = t;
  for (i = 2; i < 128; ++i) {
	t = 1.0/t + 1;
    sum[i] = sum[i-1] + t;
  }
  int n, m;
  cin >> n;
  while (scanf("%d", &m) != EOF) {
    printf("%.3lf\n", sum[m]);
  }
  return 0;
}