--------- |...|...---- |.0.+......| |...|0|..|.| -----------....|0| |......0.........| |.|.|.0--.|.|..|^| |...|0....|....|^| --0|.0.-------+-|^| --...0..|....|...|^| |...0|..#....#.0.|^| |..0...-|....|...|^-- |.0-----|....|----..| |@.|<^^^+....+^^^^..| --------------------- Lable the boulders: --------- |...|...---- |.K.+......| |...|L|..|.| -----------....|M| |......J.........| |.|.|.H--.|.|..|^| |...|G....|....|^| --E|.F.-------+-|^| --...D..|....|...|^| |...C|..#....#.N.|^| |..B...-|....|...|^-- |.A-----|....|----..| |@.|<^^^+....+^^^^..| --------------------- First push E two spaces north: --------- |...|...---- |.K.+......| |...|L|..|.| -----------....|M| |......J.........| |E|.|.H--.|.|..|^| |@..|G....|....|^| --.|.F.-------+-|^| --...D..|....|...|^| |...C|..#....#.N.|^| |..B...-|....|...|^-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Now push J five tiles east, so that it is lined up with the tiny wall. --------- |...|...---- |.K.+......| |...|L|..|.| -----------....|M| |..........@J....| |E|.|.H--.|.|..|^| |...|G....|....|^| --.|.F.-------+-|^| --...D..|....|...|^| |...C|..#....#.N.|^| |..B...-|....|...|^-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Take M, obviously. --------- |...|...---- |.K.+......| |...|L|..|.| -----------....|.| |...........J...@| |E|.|.H--.|.|..|.| |...|G....|....|^| --.|.F.-------+-|^| --...D..|....|...|^| |...C|..#....#.N.|^| |..B...-|....|...|^-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- The remainder of the boulders will one-by-one be pushed into this spot, where you are now standing, and then you go around north and take them. The next one to go is J. --------- |...|...---- |.K.+......| |...|L|..|.| -----------....|.| |..............@J| |E|.|.H--.|.|..|.| |...|G....|....|^| --.|.F.-------+-|^| --...D..|....|...|^| |...C|..#....#.N.|^| |..B...-|....|...|^-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- After pushing J into the next pit, push H one tile north, then bring it east and take it the same way. --------- |...|...---- |.K.+......| |...|L|..|.| -----------....|.| |................| |E|.|..--.|.|..|.| |...|G....|....|@| --.|.F.-------+-|.| --...D..|....|...|^| |...C|..#....#.N.|^| |..B...-|....|...|^-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Open the door and bring K out, past L and just past the wall... --------- |...|...---- |...-.@K...| |...|L|..|.| -----------....|.| |................| |E|.|..--.|.|..|.| |...|G....|....|.| --.|.F.-------+-|.| --...D..|....|...|^| |...C|..#....#.N.|^| |..B...-|....|...|^-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Then bring it south three tiles... --------- |...|...---- |...-......| |...|L|..|.| -----------..@.|.| |............K...| |E|.|..--.|.|..|.| |...|G....|....|.| --.|.F.-------+-|.| --...D..|....|...|^| |...C|..#....#.N.|^| |..B...-|....|...|^-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- This lets you bring K east and take it. After doing so, bring N out and take it in much the same way. --------- |...|...---- |...-......| |...|L|..|.| -----------....|.| |................| |E|.|..--.|.|..|.| |...|G....|....|.| --.|.F.-------|-|.| --...D..|....|...|@| |...C|..#....#...|.| |..B...-|....|...|^-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Push L one tile north and move it west into the middle of the room. --------- |...|...---- |.L@-......| |...|.|..|.| -----------....|.| |................| |E|.|..--.|.|..|.| |...|G....|....|.| --.|.F.-------|-|.| --...D..|....|.....| |...C|..#....#...|.| |..B...-|....|...|^-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Now get behind L and bring it out in exactly the same way as K. --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |E|.|..--.|.|..|.| |...|G....|....|.| --.|.F.-------|-|.| --...D..|....|.....| |...C|..#....#...|@| |..B...-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Right, now the hard part. We need every single one of these boulders, so we absolutely have to get behind the diagonal line of them, without moving any of them into an inextricable spot. Here's how... NO NO NO This Is Wrong: NO NO Move D exactly one tile east. NO NO NO NO --------- NO NO |...|...---- NO NO |...-......| NO NO |...|.|..|.| NO NO -----------....|.| NO NO |................| NO NO |E|.|..--.|.|..|.| NO NO |...|G....|....|.| NO NO --.|.F.-------|-|.| NO NO --...@D.|....|.....| NO NO |...C|..#....#...|.| NO NO |..B...-|....|...|.-- NO NO |.A-----|....|----..| NO NO |>.|<^^^+....+^^^^..| NO NO --------------------- NO NO NO NO By itself, this gains us nothing. NO NO More precisely, it gains us nothing NO NO while we're on this side of the NO NO diagonal line. But if we can get NO NO behind, it's now possible to do NO NO some things that previously would NO NO have gotten boulders stuck. NO NO NO NO To get behind it, push G exactly NO NO two tiles south. NO NO NO NO --------- NO NO |...|...---- NO NO |...-......| NO NO |...|.|..|.| NO NO -----------....|.| NO NO |................| NO NO |E|.|..--.|.|..|.| NO NO |...|.....|....|.| NO NO --.|.F@-------|-|.| NO NO --....DG|....|.....| NO NO |...C|..#....#...|.| NO NO |..B...-|....|...|.-- NO NO |.A-----|....|----..| NO NO |>.|<^^^+....+^^^^..| NO NO --------------------- NO NO NO NO It's now both safe and also possible NO NO to push F one tile to the west NO NO NO NO --------- NO NO |...|...---- NO NO |...-......| NO NO |...|.|..|.| NO NO -----------....|.| NO NO |................| NO NO |E|.|..--.|.|..|.| NO NO |...|.....|....|.| NO NO --.|F@.-------|-|.| NO NO --....DG|....|.....| NO NO |...C|..#....#...|.| NO NO |..B...-|....|...|.-- NO NO |.A-----|....|----..| NO NO |>.|<^^^+....+^^^^..| NO NO --------------------- NO NO NO NO We need to push F north, but doing NO NO so right now will get it stuck. NO NO We need E out of there. To make NO NO room, push B two tiles east. NO NO NO NO --------- NO NO |...|...---- NO NO |...-......| NO NO |...|.|..|.| NO NO -----------....|.| NO NO |................| NO NO |E|.|..--.|.|..|.| NO NO |...|.....|....|.| NO NO --.|F..-------|-|.| NO NO --....DG|....|.....| NO NO |...C|..#....#...|.| NO NO |...@B.-|....|...|.-- NO NO |.A-----|....|----..| NO NO |>.|<^^^+....+^^^^..| NO NO --------------------- NO NO NO NO Now bring E south until it is NO NO next to C. NO NO NO NO --------- NO NO |...|...---- NO NO |...-......| NO NO |...|.|..|.| NO NO -----------....|.| NO NO |................| NO NO |.|.|..--.|.|..|.| NO NO |...|.....|....|.| NO NO --.|F..-------|-|.| NO NO --.@..DG|....|.....| NO NO |..EC|..#....#...|.| NO NO |....B.-|....|...|.-- NO NO |.A-----|....|----..| NO NO |>.|<^^^+....+^^^^..| NO NO --------------------- NO NO NO NO Push F all the way north and take it. NO NO NO NO --------- NO NO |...|...---- NO NO |...-......| NO NO |...|.|..|.| NO NO -----------....|.| NO NO |................| NO NO |.|.|..--.|.|..|.| NO NO |...|.....|....|.| NO NO --.|...-------|-|.| NO NO --....DG|....|.....| NO NO |..EC|..#....#...|.| NO NO |....B.-|....|...|.-- NO NO |.A-----|....|----..| NO NO |>.|<^^^+....+^^^.@.| NO NO --------------------- NO NO NO NO Now put E back where it was. NO NO NO NO --------- NO NO |...|...---- NO NO |...-......| NO NO |...|.|..|.| NO NO -----------....|.| NO NO |................| NO NO |E|.|..--.|.|..|.| NO NO |@..|.....|....|.| NO NO --.|...-------|-|.| NO NO --....DG|....|.....| NO NO |...C|..#....#...|.| NO NO |....B.-|....|...|.-- NO NO |.A-----|....|----..| NO NO |>.|<^^^+....+^^^...| NO NO --------------------- Let's try a different approach to the diagonal... --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |E|.|..--.|.|..|.| |...|G....|....|.| --@|.F.-------|-|.| --...D..|....|.....| |...C|..#....#...|.| |..B...-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Start out by pusing G two tiles south. --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |E|.|..--.|.|..|.| |...|.....|....|.| --.|.F@-------|-|.| --...D.G|....|.....| |...C|..#....#...|.| |..B...-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Push F one tile west. --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |E|.|..--.|.|..|.| |...|.....|....|.| --.|F@.-------|-|.| --...D.G|....|.....| |...C|..#....#...|.| |..B...-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Now go around and push B one tile east. --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |E|.|..--.|.|..|.| |...|.....|....|.| --.|F..-------|-|.| --...D.G|....|.....| |...C|..#....#...|.| |..@B..-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Push E south until it is next to C. --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |.|.|..--.|.|..|.| |...|.....|....|.| --.|F..-------|-|.| --.@.D.G|....|.....| |..EC|..#....#...|.| |...B..-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Now push D one tile west. --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |.|.|..--.|.|..|.| |...|.....|....|.| --.|F..-------|-|.| --..D@.G|....|.....| |..EC|..#....#...|.| |...B..-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^^^^..| --------------------- Push F north all the way to the wall and take it. --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |.|.|..--.|.|..|.| |...|.....|....|.| --.|...-------|-|.| --..D..G|....|.....| |..EC|..#....#...|.| |...B..-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^^^.@.| --------------------- Do the same thing to G. --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |.|.|..--.|.|..|.| |...|.....|....|.| --.|...-------|-|.| --..D...|....|.....| |..EC|..#....#...|.| |...B..-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^^.@..| --------------------- Push D east to where G was, then north, and take it the same way. --------- |...|...---- |...-......| |...|.|..|.| -----------....|.| |................| |.|.|..--.|.|..|.| |...|.....|....|.| --.|...-------|-|.| --......|....|.....| |..EC|..#....#...|.| |...B..-|....|...|.-- |.A-----|....|----..| |>.|<^^^+....+^.@...| --------------------- Push E one tile north, then take it east along the same track as D.