You have a 16x16 grid of which the 4 centermost cells are always 100 degrees and the cornermost cells are always 0 degrees. All other cells start at 50 degrees.
For example, a 6x6 grid would look like this:
| 0 | 50 | 50 | 50 | 50 | 0 |
| 50 | 50 | 50 | 50 | 50 | 50 |
| 50 | 50 | 100 | 100 | 50 | 50 |
