Why do parrots know hundreds of surnames?
For example, I first found a grid named "Wu" on the ground, and then found a card named "Wu" among the cards I gave. There are 40 surnames on this card, but if you compare them carefully, you will find that if you put the card in a grid and there is a surname Wu on the ground, only one surname Wu between the two cards is coincident.
Although the covered card is upside down, the artist has actually turned the card over when he asked the parrot to identify it, and has memorized the contents of the card, so he can know what surnames are on the card at a glance and naturally calculate your surnames accurately.
Then the parrot took a piece of paper, but the artist asked the parrot to touch his mouth on the paper. These are all under his control, and the parrot is just a prop.