C1046

The guard enthusiastically said, "Student, your first year of high school is on the right side of the first teaching building. Class (21) is on the left side of the last classroom on the second floor."

In prayer's first year of high school, there were a total of 21 classes. From 1 to 10, they were science classes, from 11 to 20, they were arts classes. Class 21, on the other hand