#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int N = 200010;
int n,h[N];
ll a[N],c[N];

void add(int x,ll k){for(;x <= n; x += x & -x ) c[x] = max(c[x], k);}

ll query(int x) {
	ll res= 0;
	for (; x; x -= x & -x) res = max(res, c[x]);
	return res;
} 

int main() {
	scanf("%d", &n);
	for (int i = 1; i <= n; ++i) scanf("%d", &h[i]);
	for (int i = 1; i <= n; ++i) scanf("%lld", &a[i]);
	ll ans=0;
	for (int i = 1; i <= n; ++i) {
		ll fi = query(h[i] - 1) + a[i]; // 区间查询最大值
		add(h[i], fi);           // 塞入当前 fi 的值
		ans = max(ans, fi);      // 记录答案
	}
	printf("%lld", ans);
	return 0;
}

#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int N = 200010;
int n,h[N];
ll a[N],c[N];

void add(int x,ll k){for(;x <= n; x += x & -x ) c[x] = max(c[x], k);}

ll query(int x) {
	ll res= 0;
	for (; x; x -= x & -x) res = max(res, c[x]);
	return res;
} 

int main() {
	scanf("%d", &n);
	for (int i = 1; i <= n; ++i) scanf("%d", &h[i]);
	for (int i = 1; i <= n; ++i) scanf("%lld", &a[i]);
	ll ans=0;
	for (int i = 1; i <= n; ++i) {
		ll fi = query(h[i] - 1) + a[i]; // 区间查询最大值
		add(h[i], fi);           // 塞入当前 fi 的值
		ans = max(ans, fi);      // 记录答案
	}
	printf("%lld", ans);
	return 0;
}