IndexError

Level 1 of the Dungeon
[Shop] Goetum's Assorted Antiques
  a +0 vampiric great sword (559 gold)
  a potion of resistance (260 gold)
  a +1 chain mail of fire resistance (429 gold)
  a +0 chain mail (117 gold)
  a scroll of fear (104 gold)
  a scroll of identify (52 gold)
  a +0 ring mail (104 gold)
(0, 0, D:1)
  a +0 dagger
(4, -7, D:1)
  8 stones
(5, -5, D:1)
  a +0 club
  a goblin skeleton
(5, 9, D:1)
  a +0 robe
(11, -3, D:1)
  a +0 club
  a kobold skeleton
(11, 2, D:1)
  a +0 dagger
  5 stones
(15, -18, D:1)
  a ball python skeleton
(16, 9, D:1)
  a ball python skeleton
(20, 11, D:1)
  a rat skeleton
(26, 8, D:1)
  a +0 hand axe
(26, 9, D:1)
  5 curare-tipped darts
(26, 10, D:1)
  a scroll of noise
(27, 8, D:1)
  10 gold pieces
(27, 9, D:1)
  a potion of attraction
(27, 10, D:1)
  a scroll of teleportation
(28, 8, D:1)
  a +0 ring mail
(28, 9, D:1)
  3 stones
(28, 10, D:1)
  4 stones
(34, -1, D:1)
  2 boomerangs
(47, -20, D:1)
  a +0 robe

Level 2 of the Dungeon
(0, 0, D:2)
  5 stones
(2, 10, D:2)
  a ball python skeleton
(7, -32, D:2)
  a frilled lizard corpse (skeletalised by now)
(7, 1, D:2)
  a hobgoblin skeleton
(19, -28, D:2)
  an adder corpse (skeletalised by now)
(19, -17, D:2)
  a +0 short sword
  5 stones
  a kobold skeleton
(20, -17, D:2)
  a +0 club
  a kobold skeleton
(21, -5, D:2)
  a +0 ring mail
(26, -20, D:2)
  5 boomerangs
(29, -21, D:2)
  a ball python skeleton
(33, -31, D:2)
  7 stones
(34, 11, D:2)
  a hobgoblin skeleton
(40, -26, D:2)
  a +0 chain mail
(46, -9, D:2)
  a ball python skeleton
(47, 8, D:2)
  a bat corpse (skeletalised by now)
(48, 8, D:2)
  an orb of wrath

Level 3 of the Dungeon
(0, 0, D:3)
  a rat corpse (skeletalised by now)
(27, 16, D:3)
  a +0 trident
(27, 33, D:3)
  a +0 robe
(28, 33, D:3)
  18 gold pieces
(30, 35, D:3)
  a +0 ring mail
(48, 40, D:3)
  2 stones
(51, 36, D:3)
  a +0 club
(52, 9, D:3)
  a hound corpse
(56, 21, D:3)
  a +0 spear
(58, 14, D:3)
  a +0 club
(60, 7, D:3)
  a +0 dagger
(61, 38, D:3)
  a +0 ring mail
(65, 27, D:3)
  a ball python corpse (skeletalised by now)
(66, 10, D:3)
  8 stones