Virus

As a scientist, you have discovered a deadly virus that you are researching safely in isolated rooms. But oh, no! An earthquake occurs, shattering the containers in which the virus is stored. An emergency system activates, securing the laboratory and closing the vents.

You only have a short time to destroy the virus before the emergency system shuts down and opens the vents. You put on a protective suit and think about how to do it.

Your lab has 16 rooms, connected by airtight doors. It has one entrance and one exit, as shown in the picture. The virus is active in all rooms except the entrance, which remained uninfected.

To destroy the virus, you must enter each infected room and press the room's self-destruct button.

Since the emergency system is activated, you cannot leave the room without pressing the button and liquidating it. As a result, you cannot enter the room twice.

You can only enter the laboratory through the entrance and leave through the exit.

How can you destroy the virus in each infected room and survive?