Our school has 17 weeks of classes. If there are 34 class hours, there will be one big class every week, including two classes (one 45-minute class). If there is 5 1 class, it is also a large class, but it includes 3 classes, or it is divided into two weeks, one week or two large classes (two classes). If there are 64 classes, it is a large class. So there is 1 class hour, 1 45-minute class.