The difference between the guest room on the seventh floor and the parking lot is seven floors.

Go up to 14th floor, down to 5th floor, down to 3rd floor, and finally up to 6th floor, that is, finally up to14-5-3+6 =+12nd floor, that is, to13rd floor.

* * * on the eighth floor, down from the eighth floor, *** 16 floor.