<>;<>;
@XY=map[glob],<>;
$a[$_]=++$i for@{pop@XY};

for$i(1..$#a){
	$t=$a[$i];
	$t==@$_[0]?++$t:$t==@$_[1]&&--$t for@XY,@xy;
	if($t<$i){
		push@xy,map[$_,$_+1],$t..$i-1
	}elsif($i<$t){
		push@xy,map[-$_,-$_+1],-$t+1..-$i
	}
}

print@xy.$/,map"@$_\n",@xy