Hi, I'm having trouble with this question. Can anyone explain how to do it?

A students' council executive could consist of a president, vice-president, secretary, treasurer, social convenor, fundraising chair, and four grade representatives. Suppose ten students have been nominated to fill these positions. Five of the nominees are from grade 12, three are from grade 11, and the other two are a grade 9 and a grade 10.

In how many ways can the council be schosen if the president and vice-president must be grade 12 students and the grade representatives must represent their current grade level?

The answer at the back of the book is: 4320

Thanks!!