1. Build what's shown in the screenshot. ("k" can be anything, but both k's must be the same, and remember the size NxN, in this case 3x3)
2. Set one of the structure blocks to Save and the other to Corner.
3. Click on the 'DETECT' button in the Save block.
4. The detect fails. If it were to succeed it would be with a size of N by N by 1 (lwh)
5. Move the 'Corner' structure H+2 blocks up or down from the 'Save' block.
6. Click on the 'DETECT' button again in the Save block.
7. The detect should succeed with size N by N by H (lwh).
Raise one of your corners by two blocks. The two corner blocks are excluded from the resulting structure bounds (including vertically), so to make a one-high structure, they must take up a total of three blocks space, like so:
[media]