This is kind of strange that you get yourself locked inside your own office. Everyone has already left and the peon who has the duty to open and close the main exit of the office has also left for the day. The main exit is the only way to get out from this place but it is password protected and you do not know the password. Hopefully, you can find it by searching the office. Honestly you have no idea about where possibly you can find what you are looking for and so the only other option is to search everywhere. You will have to think very smartly.