Eliminating the impossible, all that exists is, after all, the first option.
Just as the author of the book said fundamentally, you need to take a bi-directional one.
After discovering that there are three varieties on the first floor, even up to the third or fourth floor, we never used either one-way or random ones.
With just that, we were able to make it here.
However, from here on, you might need to use not just two-way teleports, but some one-way teleports, as well.