Open at the Top

This is one of the new possible maps for Sokoban Level 1 in Hack'EM. It has 20 boulders and 18 holes, leaving 2 spare boulders.

------------------    ---- 0 boulder
|................------..| ^ hole
|................^^^^^^^.| > starting position/downstairs
|..0........----.-------^| + door
|--0--------|....|     |^|
|.....|.....|....|     |^|
|....0|0..0..0...|     |^|
|.0..0.......-----     |^|
|.....|.00.00|         |^|
|....0--.....|         |^|
-----.--------   ------|^|
 |.0..0....|   --|.....|^|
 |..0..0...|   |.+.....|^|
 |-.----...|   |-|.....|^|
 |..0...0.--   |.+.....+.|
 |.>...0..|    |-|.....|--
 |.....----    |.+.....|
 -------       --|.....|
                 -------

Strategy

------------------    ---- B r
|................------..| H u
|................^^^^^^^.| J rrrr
|..T........----.-------^| R r
|--S--------|....|     |^| T r
|.....|.....|....|     |^| S dduu uurr rrrr rrrr rrrr
|....K|L..O..R...|     |^| I ruuu uurr rrrr rrrr rrrr r
|.I..J.......-----     |^| T lddd uuuu rrrr rrrr rrrr rrrr
|.....|.MN.PQ|         |^|
|....H--.....|         |^|
-----.--------   ------|^|
 |.A..C....|   --|.....|^|
 |..B..D...|   |.+.....|^|
 |-.----...|   |-|.....|^|
 |..E...G.--   |.+.....+.|
 |.>...F..|    |-|.....|--
 |.....----    |.+.....|
 -------       --|.....|
                 -------

------------------    ---- J llll lluu uuur rrrr rrrr rrrr rrrr
|................------..| L dlll luuu uurr rrrr rrrr rrrr rrrr
|...................^^^^.| O llld llll uuuu urrr rrrr rrrr rrrr rrrr
|...........----.-------^| R llll llld llll uuuu urrr rrrr rrrr rrrr rrrr r
|--.--------|....|     |^| N ulll lllu uuuu rrrr rrrr rrrr rrrr rrrr rd
|.....|.....|....|     |^| M ulll lluu uuur rrrr rrrr rrrr rrrr rrrr dd
|....K|L..O...R..|     |^|
|........J...-----     |^|
|....H|.MN.PQ|         |^|
|.....--.....|         |^|
-----.--------   ------|^|
 |.A..C....|   --|.....|^|
 |...B.D...|   |.+.....|^|
 |-.----...|   |-|.....|^|
 |..E...G.--   |.+.....+.|
 |.>...F..|    |-|.....|--
 |.....----    |.+.....|
 -------       --|.....|
                 -------

------------------    ---- K dllu uuuu rrrr rrrr rrrr rrrr rrrr rddd
|................------..| H ullu uuuu rrrr rrrr rrrr rrrr rrrr rddd d
|........................| P ulll llll luuu uurr rrrr rrrr rrrr rrrr rrrd dddd
|...........----.-------.| Q uull llld llll uuuu urrr rrrr rrrr rrrr rrrr rrdd dddd
|--.--------|....|     |.|
|.....|.....|....|     |^|
|....K|..........|     |^|
|............-----     |^|
|....H|....PQ|         |^|
|.....--.....|         |^|
-----.--------   ------|^|
 |.A..C....|   --|.....|^|
 |...B.D...|   |.+.....|^|
 |-.----...|   |-|.....|^|
 |..E...G.--   |.+.....+.|
 |.>...F..|    |-|.....|--
 |.....----    |.+.....|
 -------       --|.....|
                 -------

------------------    ---- C rrr
|................------..| D r
|........................| B r
|...........----.-------.| A rruu uull uuuu urrr rrrr rrrr rrrr rrrr rrdd dddd d
|--.--------|....|     |.| G r
|.....|.....|....|     |.| C llll uuuu lluu uuur rrrr rrrr rrrr rrrr rrrr dddd dddd
|.....|..........|     |.| D ulll uuuu lluu uuur rrrr rrrr rrrr rrrr rrrr dddd dddd d
|............-----     |.| G uuul lllu uuul luuu uurr rrrr rrrr rrrr rrrr rrrd dddd dddd d
|.....|......|         |.| E luuu rruu uull uuuu urrr rrrr rrrr rrrr rrrr rrdd dddd dddd d
|.....--.....|         |^|
-----.--------   ------|^|
 |.A..C....|   --|.....|^|
 |...B.D...|   |.+.....|^|
 |-.----...|   |-|.....|^|
 |..E...G.--   |.+.....+.|
 |.>...F..|    |-|.....|--
 |.....----    |.+.....|
 -------       --|.....|
                 -------