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

##</code><code>##

%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

##</code><code>##

($m,%b)=(h,j,{0,[h,1]},a,{0,[p,1,j]},p,{0,[a,1,a]},h,{0,[j,1,p]})