#include<cstdio>

#include<algorithm>

using namespace std;

typedef long long ll;

struct Point{ll T,K;}a[100001];

bool operator < (const Point &a,const Point &b)

{return a.T*a.K+(a.T+b.T)*b.K<b.T*b.K+(a.T+b.T)*a.K;}

int n;

ll ans,sum;

int main()

{

	scanf("%d",&n);

	for(int i=1;i<=n;++i) scanf("%lld",&a[i].T);

	for(int i=1;i<=n;++i) scanf("%lld",&a[i].K);

	sort(a+1,a+n+1);

	for(int i=1;i<=n;++i)

	  {

	  	sum+=a[i].T;

	  	ans+=sum*a[i].K;

	  }

	printf("%lld\n",ans);

	return 0;

}