#include<cstring>

#include<algorithm>

#include<iostream>

#include<cmath>

#include<cstdio>

#include<queue>

using namespace std;

struct gua

{

	long long v,d;

	bool operator < (const gua &b)const

	{

		if(v==b.v) return d>b.d;

		return v>b.v;

	}

};//这里手残漏了个分号导致螺旋报错

priority_queue<gua>que;

int main()

{

	int a[50005],b[50005],n,i;

	long long p[50005]={0};//p[i]表示在前i天有西瓜吃的情况下（并非于i天截止）最小花费

	while(cin>>n)

	{

		for(i=1;i<=n;i++) cin>>a[i];

		for(i=1;i<=n;i++) cin>>b[i];

		while(que.size()) que.pop();//初始化队列

		gua t;

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

		{

			t.v=p[i-1]+a[i];

			t.d=i+b[i]-1;

			while(que.size()&&que.top().d<i) que.pop();//判断，当当前最优解的天数打不到i时弹出

			que.push(t);

			p[i]=que.top().v;

		}

		cout<<p[n]<<endl;

	}

}