I need this done in c++ please.

Project 3: Counting Rectangles [REC] Textbook Section: 2.8 Set Up: A 2 3 rectangular grid contains exactly eighteen different rectangles: Directions: Compute the number of different rectangles an n m rectangular grid contains for n > 0; m >O. Allow the user to choose n and m. Input: the size of the grid (ie: n = 5 and m-3 where the grid is 5 3) Output: the number of rectangles contained in the grid