Numbers in AAAA X BBBB is monitor resolution, the common one is 1920x1080. You can check this on by looking at display setting in Windows and its under Display Resolution.
When a monitor is described as X inches, it refers to physical size of the screen diagonally (doesn't affect resolution).
For maple, if you running a 1920x1080 monitor, I would use 1366x768 windowed so it would fit the display without being at fullscreen and should have some space so task bar doesn't overlap to your maple window.