Fan Tan is an ancient gambling game originated in China, our version of the game does not have gambling contents but instead tests your eyesight and memory. In this game there will be some stones on the table, and then a bowl will come down to cover some of the stones. Your task is to guess the number of stones that are left when the stones under the bowl are removed in groups of 4, that is, the remainder when the number of stones under the bowl is divided by 4. At first, the bowl will come down slowly and you can take the time to count the number of stones under the shadow of the bowl so that you can get the correct answer. As the game progresses, the bowl will come down faster and faster and there will be more stores, making the game harder and harder. There are a total of 10 levels. The more times you get the answer correctly, the higher your score.