#include <iostream>
#include <stdio.h>
using namespace std;
typedef long long llong;

int A[5111];
int B[5111];
int K[5111];
int n;

llong F[5111];

llong MAX(llong a,llong b)
{
    if (a>b)
        return a;
    else
        return b;
}

llong Sell(int fruit,int day)
{
    if (day>=K[fruit])
        return 0LL;
    else
        return (llong)A[fruit]+(llong)B[fruit]*(llong)day;
}

///Not needed
int bestfrom[5111];
int bestans=0;
///

int main()
{
    freopen("fruits.in","r",stdin);
    freopen("fruits.out","w",stdout);

    int i,j;
    llong win=0;
    llong ans=0;

    scanf("%d",&n);

    for (i=1;i<=n;i++)
    {
        scanf("%d",&A[i]);
    }

    for (i=1;i<=n;i++)
    {
        scanf("%d",&B[i]);
    }

    for (i=1;i<=n;i++)
    {
        scanf("%d",&K[i]);
    }

    for (i=1;i<=n;i++)
    {
        F[i]=0;

        if (K[i]==0)
        {
            bestfrom[i]=0;
            continue;
        }

        win=Sell(i,K[i]-1);

        for (j=i-1;j>=0;j--)
        {
            if (K[j]<K[i])
            {
                if (F[j]+win>F[i])
                    bestfrom[i]=j;

                F[i]=MAX(F[i],F[j]+win);
            }

            win+=Sell(j,K[i]-1);
        }

        if (F[i]>ans)
            bestans=i;

        ans=MAX(ans, F[i]);
    }

    printf("%lld\n",ans);
    return 0;
}