T157T1

#include<bits/stdc++.h>

using namespace std;

#define gc c=getchar()
#define r(x) read(x)
#define ll long long

template<typename T>
inline void read(T&x){
    x=0;T k=1;char gc;
    while(!isdigit(c)){if(c=='-')k=-1;gc;}
    while(isdigit(c)){x=x*10+c-'0';gc;}x*=k;
}

const int N=1e7+5;

int n;
ll c[N];

inline void insert(int x,ll v){
    for(int i=x;i<=n;i+=(i&-i)){
        c[i]=max(c[i],v);
    }
}

inline ll query(int x){
    if(x<=0)return 0;
    ll ret=0;
    for(int i=x;i;i^=(i&-i)){
        ret=max(c[i],ret);
    }
    return ret;
}

ll f[N];
int t[N];
int a[N];

vector<int>G[N];

int main(){
    freopen("fc.in","r",stdin);
    freopen("fc.out","w",stdout);
    r(n);
    for(int i=1;i<=n;++i){
        r(t[i]);
        if(i+t[i]<=n)G[i+t[i]].push_back(i);
    }
    for(int i=1;i<=n;++i){
        r(a[i]);
        for(int j=0;j<G[i].size();++j){
            insert(G[i][j],f[G[i][j]]);
        }
        f[i]=query(i-t[i])+(ll)a[i]*t[i];
    }
    ll ans=0;
    for(int i=1;i<=n;++i){
        ans=max(ans,f[i]);
    }
    printf("%lld\n",ans);
    return 0;
}