# include <iostream>
#include <stdio.h>
# include <cstdio>
using namespace std;
int a[5005],b[5005],k[5005];
int d[5005][10005];

int main()
{
//freopen("fruits.in","r",stdin);
//freopen("fruits.out","w",stdout);
int n,i;
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=0;i<k[1];i++)
{
    d[1][i]=a[1]+i*b[1];
    // cout<<1<<" "<<i<<" "<<d[1][i]<<endl;
}
for(i=k[1];i<=k[n];i++)
{
    d[1][i]=d[1][k[1]-1];
   //  cout<<1<<" "<<i<<" "<<d[1][i]<<endl;
}*/
int t,j;
int v;
int z;
for(t=1;t<=n;t++)
{
    for(i=0;i<k[t];i++)
    {
        d[t][i]=d[t-1][i]+a[t]+i*b[t];
      // cout<<t<<" "<<i<<" "<<d[t][i]<<endl;
            }
    for(i=k[t];i<=k[n];i++)
    {
        d[t][i]=max(d[t][k[t]-1],d[t-1][i]);
     //   cout<<t<<" "<<i<<" "<<d[t][i]<<endl;
    }
}
v=0;
for(i=0;i<k[n];i++)
{
    v=max(v,d[n][i]);
}
cout<<v<<endl;
return 0;
}