253bf280 ​

input = fill #0 (fill #1 black) |> fold (λr. rect ((r.1, r.2, r.1, r.2), teal)) #2
output = fill #0 (fill #1 black) |> fold rect #3
(VInt, HInt, UList (VInt, HInt), UList ((VInt, HInt, VInt, HInt), Color))
(7v, 13h, {(4v, 10h), (4v, 3h)}, {((4v, 10h, 4v, 10h), teal), ((4v, 4h, 4v, 9h), green), ((4v, 3h, 4v, 3h), teal)})
(10v, 11h, {(8v, 5h), (7v, 9h), (3v, 9h), (2v, 5h)}, {((8v, 5h, 8v, 5h), teal), ((7v, 9h, 7v, 9h), teal), ((4v, 9h, 6v, 9h), green), ((3v, 9h, 3v, 9h), teal), ((3v, 5h, 7v, 5h), green), ((2v, 5h, 2v, 5h), teal)})
(12v, 11h, {(9v, 8h), (9v, 3h), (2v, 10h), (2v, 2h)}, {((9v, 8h, 9v, 8h), teal), ((9v, 4h, 9v, 7h), green), ((9v, 3h, 9v, 3h), teal), ((2v, 10h, 2v, 10h), teal), ((2v, 3h, 2v, 9h), green), ((2v, 2h, 2v, 2h), teal)})
(9v, 6h, {(8v, 3h), (2v, 3h)}, {((8v, 3h, 8v, 3h), teal), ((3v, 3h, 7v, 3h), green), ((2v, 3h, 2v, 3h), teal)})
(3v, 3h, {(2v, 2h)}, {((2v, 2h, 2v, 2h), teal)})
(5v, 6h, {(4v, 5h), (2v, 2h)}, {((4v, 5h, 4v, 5h), teal), ((2v, 2h, 2v, 2h), teal)})
(7v, 6h, {(7v, 4h), (4v, 2h), (2v, 4h)}, {((7v, 4h, 7v, 4h), teal), ((4v, 2h, 4v, 2h), teal), ((3v, 4h, 6v, 4h), green), ((2v, 4h, 2v, 4h), teal)})
(12v, 11h, {(5v, 11h), (10v, 4h), (6v, 2h), (5v, 7h), (2v, 4h)}, {((5v, 11h, 5v, 11h), teal), ((10v, 4h, 10v, 4h), teal), ((6v, 2h, 6v, 2h), teal), ((5v, 8h, 5v, 10h), green), ((5v, 7h, 5v, 7h), teal), ((3v, 4h, 9v, 4h), green), ((2v, 4h, 2v, 4h), teal)})
(12v, 13h, {(6v, 13h), (11v, 2h), (10v, 9h), (8v, 2h), (6v, 7h), (2v, 11h), (2v, 3h)}, ?)