#include <cstdio>
#include <algorithm>
#define LL long long
#define oo 0x3f7f7f7f
using namespace std;

const int nma=155;
int n,val[nma],num[nma];//输入 
int dso[nma],uso[nma],bo[nma];//树 
int ans[nma][nma];//意义同题解 
int i,j,l,r,d,t;


void dsea(int t,int len,int red){//向下搜索 
	if(num[t]==num[l]+1){//剪枝 2 
		ans[l][r]=max(ans[l][r],red+val[len+1]+ans[l+1][t-1]);
		return;
	}
	for(int ion=dso[t];ion>=l;ion=bo[ion]){
		if(red+ans[ion+1][t-1]+val[len+1+ion-l]>ans[l][r])//剪枝 1 
			dsea(ion,len+1,red+ans[ion+1][t-1]);
	}
	return;
}

void usea(int t,int len,int red){//向上搜索
	if(t==l)	ans[l][r]=max(ans[l][r],red+val[len]);
	for(int ion=uso[t];ion>=l;ion=bo[ion]){
		if(red+ans[ion+1][t-1]+val[len+1+ion-l]>ans[l][r])//剪枝 1
			usea(ion,len+1,red+ans[ion+1][t-1]);
	}
	if(num[t]>num[l]){//剪枝 2
		if(num[t]==num[l]+1){//剪枝 2
			ans[l][r]=max(ans[l][r],red+val[len+1]+ans[l+1][t-1]);
			return;
		}
		for(int ion=dso[t];ion>=l;ion=bo[ion]){
			if(red+ans[ion+1][t-1]+val[len+1+ion-l]>ans[l][r])
				dsea(ion,len+1,red+ans[ion+1][t-1]);
		}
	}
	return;
}

int main()
{
	//freopen("1.in","r",stdin);
	scanf("%d",&n);
	for(i=1;i<=n;i++)
		for(j=1;j<=n;j++)
			ans[i][j]=-oo;//第一次动规时ans有负值. 
	for(i=1;i<=n;i++){
		scanf("%d",&val[i]);
		for(t=1;(t<<1)<=i;t++)	val[i]=max(val[i],val[t]+val[i-t]);
		ans[i][i]=val[1];
		ans[i+1][i]=0;
	}
	ans[1][0]=0;
	for(i=1;i<=n;i++){
		scanf("%d",&num[i]);
		for(j=i-1;j;j--)
			if(num[j]==num[i])	{ bo[i]=j; break; }
		for(j=i-1;j;j--)
			if(num[j]+1==num[i])	{ dso[i]=j; break; }
		for(j=i-1;j;j--)
			if(num[j]==num[i]+1)	{ uso[i]=j; break; }
	}
	//以上为读入,ans初始化,建树. 
	
	for(d=1;d<n;d++){
		for(l=1,r=l+d;r<=n;l++,r++){
			for(t=l;t<r;t++){
				ans[l][r]=max(ans[l][r],ans[l][t]+ans[t+1][r]);
			}
			usea(r,1,0);
		}
	}
	//以上为第一次动规 
	
	for(i=1;i<=n;i++)
		if(ans[i][i]<0)	 ans[i][i]=0;
	for(d=1;d<n;d++){
		for(l=1,r=l+d;r<=n;l++,r++){
			for(t=l;t<r;t++){
				ans[l][r]=max(ans[l][r],ans[l][t]+ans[t+1][r]);
			}
		}
	}
	//以上为第二次动规 
	
	printf("%d",ans[1][n]);
	return 0;
}