#include 
#include 
#include 
//#include 
using namespace std;
typedef long long ll;
const int maxn = 2e5 + 10;
ll segment_tree[maxn * 3];
void build(int L, int R, int pos) {
    if(L == R) {
        segment_tree[pos] = 0;
    }
    else {
        int mid = (L + R) / 2;
        build(L, mid, 2 * pos);
        build(mid + 1, R, 2 * pos + 1);
        segment_tree[pos] = max(segment_tree[2 * pos], segment_tree[2 * pos + 1]);
    }
}
// L R   i L R j L R
ll query(int L, int R, int pos, int i, int j) {
    if(i <= L and R <= j) {
        return segment_tree[pos];
    }
    if(R < i or j < L) {
        return 0;
    }
    int mid = (L + R) / 2;
    return max(query(L, mid, 2 * pos, i, j), query(mid + 1, R, 2 * pos + 1, i, j));
}
void update(int L, int R, int pos, int idx, ll new_val) {
    if(L == R) {
        segment_tree[pos] = new_val;
        return;
    }
    int mid = (L + R) / 2;
    if(idx <= mid) {
        update(L, mid, 2 * pos, idx, new_val);
    }
    else {
        update(mid + 1, R, 2 * pos + 1, idx, new_val);
    }
    segment_tree[pos] = max(segment_tree[2 * pos], segment_tree[2 * pos + 1]);

}
int main() {
    ios_base::sync_with_stdio(false);
    int n;
    cin >> n;
    vector h(n), a(n);
    for(int i = 0; i < n; i++) {
        cin >> h[i];
    }
    for(int i = 0; i < n; i++) {
        cin >> a[i];
    }
    build(0, n + 1, 1);
    for(int i = 0; i < n; i++) {
        ll max_dp = query(0, n + 1, 1, 0, h[i]);
        update(0, n + 1, 1, h[i], max_dp + a[i]);
    }
    cout << query(0, n + 1, 1, 0, n + 1) << endl;
   
    return 0;
}