Given the width and height of a rectangular grid, return the total number of rectangles (NOT counting squares) that can be found on this grid.
For example, width = 3, height = 3 (see diagram below):
__ __ __ |__|__|__| |__|__|__| |__|__|__|
In this grid, there are 4 2x3 rectangles, 6 1x3 rectangles and 12 1x2 rectangles. Thus there is a total of 4 + 6 + 12 = 22 rectangles. Note we don't count 1x1, 2x2 and 3x3 rectangles because they are squares.
|-||rectangles with equals sides (squares) should not be counted.|
|-||width and height will be between 1 and 1000 inclusive.|