$n=<>;
$a=<>;
@b1=sort{$a<=>$b}<>=~/\d+/g;
$c=<>;
@d1=sort{$b<=>$a}<>=~/\d+/g;
$\=0;

for(1..$n){
	@b=@b1 if!@b;
	@d=@d1 if!@d;
	if(@b<@d){
		$b=pop@b;
		$\++if@r=grep{$b>$d[$_]}0..@d-1;
		splice(@d,$r[0],1);
	}else{
		$d=pop@d;
		$\++if@r=grep{$b[$_]>$d}0..@b-1;
		splice(@b,$r[0],1);
	}
}
print