sub f{$y=$x<$y+$d?$x:$y+$d;}
@$_=glob<>.2e9for a..c;
$p=-2e9;
while($u=$b[$i],$v=$c[$j]){
	if($u<$v){
		f$d=$u-$p;
		$x=$y;
		$p=$u;
		++$i;
	}else{
		f$d=$v-$p;
		$x+=$d;
		$p=$v;
		++$j;
	}
}
print$y;