On what floor of the building does the Frank family hide?

The Frank family lives on the second and third floors of the secret annex. In 1940, Otto Frank had rented the entire house for both residential and business purposes. After Anne's sister, Margot, is called up to serve in a German labor camp, the Frank family goes into hiding in the secret annex.
The lower floors of the annex are still used for business purposes, but the upper floors are where the Frank family is forced to hide. As one would imagine, it was very difficult to gain access to the secret annex. In order to get there, you had to go through a secret entrance hidden behind a revolving bookcase.
Things started to get particularly dangerous for the Franks when the owners of the property sold it. Then everyone had to be even more careful than usual. They would have to hide not only from the Nazis, but also from the new owners of the house.