#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll a[1000005];
//FeNwIcK tReE
int t[1000005];
ll dp[1000005];
ll mx[1000005];
int n;
inline int read(){
	int x=0;
	char c=getchar()-48;
	while(c<0 || c>9)c=getchar()-48;
	while(c>=0 && c<=9){
		x=x*10+c;
		c=getchar()-48;
	}
}
vector<int>v[1000005];
void upd(int pos,ll val){
	for(;pos<=n;pos+=pos&(-pos))mx[pos]=max(mx[pos],val);
}
ll query(int pos){
	ll ans=0;
	for(;pos>0;pos-=pos&(-pos))ans=max(ans,mx[pos]);
	return ans;
}
int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;i++)scanf("%d",&t[i]);
	for(int i=1;i<=n;i++){
		scanf("%lld",&a[i]);
		a[i]*=t[i];
	}
	for(int i=1;i<=n;i++)v[max(0,i-t[i])].push_back(i);
	ll ans=0;
	for(int i=0;i<=n;i++){
		ans=max(ans,dp[i]);
		if(i)upd(i+t[i],dp[i]);
		for(int x:v[i])dp[x]=query(x)+a[x];
	}
	printf("%lld",ans);
	return 0;
}