Rectangled

Chef loves [rectangles](https://en.wikipedia.org/wiki/Rectangle) and he wants to draw one with the largest area possible, but the problem is that his pen has only enough ink left to draw a total of $N$ unit length of line. Help him find the largest area of a rectangle which he can draw if he wants to draw **rectangles with integral sides only**. **Note** that he does **NOT** need to finish all t