How does Mr. Liu Qian's poker predict the role of magic?

The performer first put the prophecy note in an envelope and put it in the audience's pocket. Then divide a deck of playing cards into two parts, and let the audience cross-wash each other (turn one pile of cards upside down, cross it to another pile and repeat it several times). Finally, open the envelope for the audience to operate and verify the correctness of the prediction. Forecast content: 1. There are 23 cards with their backs facing up. 2. The number of cards with face up shall not exceed 1 1.

I wonder if there is a magic master here. Teach me! Thank you very much If it is inconvenient to say, you can leave your QQ number ~ even if you don't know the answer, please leave something like "I don't know" so that I can know how many people have seen this.