@D=(0,0,-1,$|=print"\e[H\e[J");$x=30;$y=10;{select$,,$,,$,,.07;$p=($j
 %=@j=',rekcah lreP rehtona tsuJ'=~/./g)==$M{"@{*t=shift@w}"}&&"\e[H".
  "\e[B"x$t[0]."\e[C"x$t[1].$"if@j<=push@w,[$y,$x];{$D+=$D[rand@D];$_=(
   A,D,B,C)[$D%=4];/A/&&$y?$y--:/D/&&$x?--$x:/B/&$y<20?$y++:/C/&$x<60?++
    $x:redo}print$p,"\e[H","\e[B"x$y,"\e[C"x$x,$j[$M{"$y $x"}=$j++];redo}