The story of a fool and five yuan and ten yuan? Nobody knows. He was given ten yuan and five yuan, and he chose five yuan. The wise man finally smiled.

In Brazil, there is a tramp who often wanders in the market. In people's eyes, he is a real fool, and many people often like to play tricks on him. What they often do is to put a five-dollar coin and a ten-dollar coin in the palm of their hands and let him choose. He always chooses nickels. Everyone can see that he is too stupid to tell a five-dollar coin from a ten-dollar coin. He always laughs and is very happy. Therefore, every time I see him, everyone will always have fun in this way. After a while, a very kind old woman couldn't bear to ask him, "Do you really can't tell a five-dollar coin from a ten-dollar coin?" The tramp smiled and replied, "If I take a ten-dollar coin, they won't have it next time."