快三有多少种组合方式

简介：Su Can's class 1 is in the second classroom on the third floor. The first classroom is a classroom for physical education students to store sports equipment. To be precise, the third floor is the fourth floor of Class 1 and Class 2. There are four classes: Class 3, Class 4, Class 5, and Class 6. The fifth floor is Art Class 1, Art Class 2, and the studio, arranged like this.