Boomerang Boulders

This is one of the new possible maps for Sokoban Level 2 in Hack'EM and Level 1 in Nethack Fourk. It has 12 boulders and 10 holes, leaving 2 spare boulders.

         ----     0 boulder
 ---------..---   ^ hole
 |.0.0....0...--- > starting position/downstairs
 |.......|0..0..| < upstairs
---------|....0.| + door
|.^^^^^^<|...0..| ? scroll of earth
|.^------|-.-----
--^^^.0..|.0...| 
 |??|0.>....00.| 
 ---|....|.....| 
    ------------ 

Strategy

         ----     A ll
 ---------..---   B ull
 |.L.K....J...--- C uuud ddd
 |.......|I..H..| D u
---------|....G.| C llll llul ll
|.^^^^^^<|...F..| E llll llll ulll u
|.^------|-.----- D luuu dddd llll llul lluu
--^^^.A..|.C...| 
 |..|B.>....DE.| 
 ---|....|.....| 
    ------------ 

         ----     H d
 ---------..---   F lldd dlll lllu lllu ur
 |.L.K....J...--- H dlld ddll llll ulll uurr
 |.......|I..H..| G dlll dddl llll lull luur rr
---------|....G.|
|..^^^^^<|...F..|
|..------|-.-----
--.......|.....| 
 |..|..>.......| 
 ---|....|.....| 
    ------------ 

         ----     J lllr rrrd dddd dlll lllu lllu urrr r
 ---------..---   I ulll rrrr dddd ddll llll ulll uurr rr
 |.L.K....J...---
 |.......|I.....|
---------|......|
|.....^^<|......|
|..------|-.-----
--.......|.....| 
 |..|..>.......| 
 ---|....|.....| 
    ------------