IndexError

Level 1 of the Dungeon
(1, 17, D:1)
  a jackal skeleton
  a jackal skeleton
(2, 16, D:1)
  a bat skeleton
(5, 14, D:1)
  a frilled lizard skeleton
(7, 1, D:1)
  a quokka skeleton
(12, 10, D:1)
  a ball python skeleton
(16, 7, D:1)
  a +0 leather armour
(20, 6, D:1)
  a +0 leather armour
(23, -4, D:1)
  a +0 club
  a goblin skeleton
(29, -2, D:1)
  a +0 leather armour
(30, -11, D:1)
  a +0 short sword
  a stone
  a kobold skeleton
(30, 33, D:1)
  a +0 robe
(33, 14, D:1)
  6 stones
(39, 0, D:1)
  a +0 vampiric hand axe {!w}
  a goblin skeleton
(40, -16, D:1)
  a frilled lizard corpse (skeletalised by now)
(46, 25, D:1)
  a +0 robe
(48, 4, D:1)
  a +0 club
(48, 24, D:1)
  a frilled lizard skeleton
(51, 24, D:1)
  a +0 scale mail
(54, 4, D:1)
  a quokka skeleton
(56, 13, D:1)
  a +0 dagger
  a goblin skeleton

Level 2 of the Dungeon
(2, -12, D:2)
  an adder corpse (skeletalised by now)
(6, 6, D:2)
  a human skeleton
(9, 4, D:2)
  a human skeleton
(10, 4, D:2)
  a human skeleton
(10, 6, D:2)
  a human corpse (skeletalised by now)
(11, 6, D:2)
  a human corpse (skeletalised by now)
(12, 9, D:2)
  a frilled lizard corpse (skeletalised by now)
(12, 10, D:2)
  a human skeleton
(13, -2, D:2)
  a ball python corpse (skeletalised by now)
(16, -34, D:2)
  a +0 dagger
  a goblin skeleton
(16, -32, D:2)
  2 stones
(19, -35, D:2)
  a +0 leather armour
(22, -12, D:2)
  3 stones
(26, -36, D:2)
  a +0 mace
(36, -36, D:2)
  a frilled lizard skeleton
(36, -33, D:2)
  a +0 quarterstaff
(37, -33, D:2)
  a +0 sling
(37, -17, D:2)
  a quokka corpse (skeletalised by now)
(40, -9, D:2)
  a +0 club
(43, -34, D:2)
  a +0 dagger of electrocution

Level 3 of the Dungeon
(10, 17, D:3)
  a frilled lizard skeleton
(15, 14, D:3)
  a +0 flail
  a +0 leather armour
  an orc corpse
(18, 3, D:3)
  a +0 ring mail
(20, 21, D:3)
  a ball python corpse
(20, 22, D:3)
  6 stones
(33, 25, D:3)
  12 gold pieces
(44, 21, D:3)
  10 gold pieces