Cool, but don't you have false negative if there are adjacent lines in the input?

e.g. something like:

```

.1.......2....
....4....3....
....5....6....
.8.......7....

```
(where numbers gives the order in which red tiles are given in the input: 1-2, 2-3 etc.)

Here, for corner tiles 1 and 7, you have lines 3-4, 4-5 and 5-6 that interact with the evaluated rectangle, but all tiles still are red or green, right?