#include <cstdio>
#include <algorithm>
#define INF 987654321
using namespace std;
int N, S[10010], T[10010], DT[10010][10010];

int solve(int k, int s)
{
    int ans = -INF;
    if( k >= N ) return -INF;
    if( k == N-1 ) return S[k]+(s*T[k]);
    if( DT[k][s] == 0 )
    {
        ans = solve(k+1, s+1);
        ans = max(ans, solve(k+2, s+1));
        DT[k][s] = ans + S[k]+(s*T[k]);
    }
    return DT[k][s];
}
int main()
{
    freopen(".20.in","r",stdin);
    freopen(".20.out","w",stdout);
    scanf("%d", &N);
    for(int i = 0 ; i < N ; i++ )
        scanf("%d", S+i);
    for(int i = 0 ; i < N ; i++ )
        scanf("%d", T+i);
    printf("%d", solve(0,0));
}