Count Carefully

"Count Carefully" is one of the new possible maps for Sokoban Level 3 in Hack'EM. It has 12 boulders and 13 holes, leaving one spare hole.

    -------------- 0 boulder
  ---.....---....| ^ hole
 --...--.0..|..0.| > starting position/downstairs
 |.00--|.>0..0.--- < upstairs
--..^--|^|-...--   + door
|.^-0.-|^|-----
|.|^0..|^|------
|.--^..0^|.....|
|.0..^---|.....|
-----^---|..<..|
 |...^^^.+.....|
 |.00----|.....|
 |...|   -------
 -----

Strategy

The solution below uses all boulders and ensures that there is a path to the up stair:

    -------------- B rr
  ---.....---....| C u
 --...--.A..|..D.| A ldd*
 |.GF--|.>B..C.--- B llll dd*
--..^--|^|-...--   C dlll lldd d*
|.^-H.-|^|-----    D lldl llll dddd*
|.|^I..|^|------
|.--^..E^|.....|
|.J..^---|.....|
-----^---|..<..|
 |...^^^.+.....|
 |.KL----|.....|
 |...|   -------
 -----

    -------------- E lld*
  ---.....---....| F d*
 --...--....|....| J rrrd*
 |.GF--|.>.....--- I l*
--..^--|.|-...--   H dd*
|.^-H.-|.|-----    G rddd ddrd d*
|.|^I..|.|------   K urrr*
|.--^..E.|.....|   L urrr*
|.J..^---|.....|
-----^---|..<..|
 |...^^^.+.....|
 |.KL----|.....|
 |...|   -------
 -----

Next level

To be written.