#include <bits/stdc++.h>
#define ll long long
#define int long long
using namespace std;
ll maxn[1000006], f[1000006], n, a[1000006], ans;
int t[1000006];
struct node {
	int name, num, id;
	bool operator<(const node& p)const {
		return name > p.name;
	}
};
priority_queue<node> que;
inline int lowbit(int p) {
	return p & -p;
}
inline void add(int p, int q) {
	while (p <= n) {
		maxn[p] = max(maxn[p], q);
		p += lowbit(p);
	}
}
inline int query(int p) {
	int cnt = 0;
	while (p >= 1) {
		cnt = max(cnt, maxn[p]);
		p -= lowbit(p);
	}
	return cnt;
}
signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> t[i];
	}
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
	}
	for (int i = 1; i <= n; i++) {
		while (que.size()) {
			if (que.top().name <= i) {
				add(que.top().id, que.top().num);
//				cout << que.top().id << ' ' << que.top().num << "[]\n";
				que.pop();
			} else {
				break;
			}
		}
//		cout << maxn[1] << "!!!\n";
		f[i] = query(i - t[i]) + a[i] * t[i];
		ans = max(ans, f[i]);
		que.push(node{i + t[i], f[i], i});
//		cout << f[i] << ' ' << maxn[i] << "||";
	}
	cout << ans;
}