#include <iostream>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 2e5 + 10;
ll segment_tree[maxn * 3];

void build(int L, int R, int position) {
    if(L == R) {
        segment_tree[position] = 0;
    }
    else {
        int middle = (L + R) / 2;
        build(L, middle, 2 * position);
        build(middle + 1, R, 2 * position + 1);
        segment_tree[position] = max(segment_tree[2 * position], segment_tree[2 * position + 1]);
    }
}
// L R    i L R j   L R
ll query(int L, int R, int position, int i, int j) {
    if(i <= L and R <= j) {
        return segment_tree[position];
    }
    if(R < i or j < L) {
        return 0;
    }
    int middle = (L + R) / 2;
    return max(query(L, middle, 2 * position, i, j), query(middle + 1, R, 2 * position + 1, i, j));
}
void update(int L, int R, int position, int idx, ll new_value) {
    if(L == R) {
        segment_tree[position] = new_value;
        return;
    }
    int middle = (L + R) / 2;
    if(idx <= middle) {
        update(L, middle, 2 * position, idx, new_value);
    }
    else {
        update(middle + 1, R, 2 * position + 1, idx, new_value);
    }
    segment_tree[position] = max(segment_tree[2 * position], segment_tree[2 * position + 1]);
}
int main() {
    int n;
    cin >> n;
    vector<ll> heights(n), values(n), dp(n + 1);
    for(int i = 0; i < n; i++) {
        cin >> heights[i];
    }
    for(int i = 0; i < n; i++) {
        cin >> values[i];
        dp[i] = values[i];
    }
    ll res = 0;
    build(0, n, 1);
    for(int i = 0; i < n; i++) {
        ll max_dp = query(0, n, 1, 0, heights[i]);
        update(0, n, 1, heights[i], max_dp + values[i]);
//        for(int j = 0; j < i; j++) {
//            if(heights[j] < heights[i]) {
//                max_dp = max(max_dp, dp[j]);
//            }
//        }
//        dp[i] = max_dp + values[i];
//        res = max(res, dp[i]);
    }
    cout << query(0, n, 1, 0, n) << endl;

    return 0;
}