This one won't explain itself when you run it.

#!/usr/bin/perl
do shift;{($t[$h],$*,$m)=@{$b{$m}{$t[$h]||0}};$h+=$*;$m?redo:die@t,$/}
[download]

If you can't figure out what the input file is supposed to look like, here are some samples:

• %b=(1,{0,[0,1],1,[0,1,2]},2,{0,[0,1,3],1,[1,1,2]},3,{0,[1,-1,4],1,[1,1
  ,3]},4,{0,[0,-1,5],1,[1,-1,4]},5,{0,[(1)x3],1,[1,-1,5]}),($m,@t)=(1)x7
  [download]

• <Reveal this spoiler or all spoilers in this node or all in this thread>