There are three bookshelves in the first room. If you look for the bookshelf carefully, there will be two photos, which are important clues. One is a picture of chess, and the other is where the chess is put. One * * * five chess sets (some may be incomplete), and two on the left and right bookshelves. The base is a magnet. Listen carefully when you play it and put it away when you hear a click. There are three on the desk (there are three on the desktop) ...

2.

In the second room, when you see nine columns of buttons, the key is to press the order of these columns. Look at a small picture on the wall, push it sideways and take out a drawing inside. It seems that this is a sequence diagram, but after careful correspondence, you find that it can't correspond to the positions of the columns in the room. In fact, the real order is on the opposite side of the picture. After pressing the buttons in sequence, a screen will light up overhead. Take out the chessboard in the table and take a picture. ...

3.

The third room. There is a symbol on the right wall of the promenade, which is a hint. The four peaks represent the numerical order, and the higher the number, the higher the peak value. Then enter and pass through infrared rays to reach the other side, and the four buttons are pressed at the same time. There are four small screens, the first one stands for 1, the second one stands for 7, the third one stands for Roman numerals corresponding to 8, and the fourth one stands for traditional 9.