There were exactly 28 students in Ms. Pine's class. She gave each student a piece of paper. Each student put his or her name on the piece
of paper.

1/4 of the students put their names on the right side of the paper.
3/7 of the students put their names on the left side of the paper.
The remaining students put their names on the center of the paper.

What is the total number of students in Ms. Pine's class who put their
names on the center of the paper