868de0fa ​

input = fill #0 (fill #1 black) |> fold (λr. rect ((r.1 - 1, r.2 - 1, r.3 + 1, r.4 + 1), blue)) #2 |> fold (λr. rect (r, black)) #2
output = fill #0 (fill #1 black) |> fold (λr. rect ((r.1 - 1, r.2 - 1, r.3 + 1, r.4 + 1), blue)) #2 |> fold (λr. rect (r, red)) #3 |> fold (λr. rect (r, orange)) #4
(VInt, HInt, UList (VInt, HInt, VInt, HInt), UList (VInt, HInt, VInt, HInt), UList (VInt, HInt, VInt, HInt))
(10v, 10h, {(7v, 2h, 9v, 4h), (2v, 2h, 3v, 3h), (4v, 8h, 4v, 8h)}, {(2v, 2h, 3v, 3h)}, {(7v, 2h, 9v, 4h), (4v, 8h, 4v, 8h)})
(10v, 10h, {(2v, 6h, 5v, 9h), (2v, 2h, 2v, 2h)}, {(2v, 6h, 5v, 9h)}, {(2v, 2h, 2v, 2h)})
(20v, 20h, {(14v, 14h, 19v, 19h), (2v, 2h, 4v, 4h), (11v, 4h, 15v, 8h), (5v, 14h, 8v, 17h), (3v, 8h, 4v, 9h)}, {(14v, 14h, 19v, 19h), (5v, 14h, 8v, 17h), (3v, 8h, 4v, 9h)}, {(2v, 2h, 4v, 4h), (11v, 4h, 15v, 8h)})
(11v, 11h, {(8v, 2h, 10v, 4h), (4v, 7h, 5v, 8h), (3v, 3h, 3v, 3h)}, {(4v, 7h, 5v, 8h)}, {(8v, 2h, 10v, 4h), (3v, 3h, 3v, 3h)})
(15v, 15h, {(11v, 8h, 14v, 11h), (3v, 3h, 7v, 7h)}, {(11v, 8h, 14v, 11h)}, {(3v, 3h, 7v, 7h)})
(20v, 20h, {(9v, 12h, 16v, 19h), (2v, 14h, 4v, 16h), (13v, 3h, 17v, 7h), (4v, 3h, 9v, 8h)}, ?, ?)