perl -we '@a=map{[split//]}<>;$x=0;$x++until$a[0][$x]eq"X";$y=0;my@r,@q;while($y<$#a){$y++;if("#"eq$a[$y][$x+1]){if("#"eq$a[$y][$x-1]){print "backtracking";$a[$y-1][$x]="#";$y-=2;$x=pop@q;pop@r}else{$a[$y-1][$x--]="L";push@r,"l";push@q,$x+1;print "trying to go left\n"}}else{print "trying to go right\n";push@r,"r";$a[$y-1][$x++]="R";push@q,$x-1}print "$y, $x\n";print@r,"\n";map {print "$_, "} @q;print "\n";map {print @{$_}}@a; print "\n\n\n\n"}'