#include <bits/stdc++.h>
using namespace std;

struct cmp
{
    bool operator()(pair<int, int> &a, pair<int, int> &b)
    {
        return (a.second == b.second) ? (a.first < b.second) : (a.second < b.second);
    }
};

int maximumHealthiness(int N, int R, vector<int> &P, vector<int> &H)
{

    vector<pair<int, int>> a(N);

    for (int i = 0; i < N; i++)
    {
        a[i].first = P[i];
        a[i].second = H[i];
    }

    sort(a.begin(), a.end());

    priority_queue<pair<int, int>, vector<pair<int, int>>, cmp> pq;
    int ans = 0;
    for (int i = 0; i < N; i++)
    {

        while (!pq.empty() && (pq.top().first + a[i].first) > R)
        {
            pq.pop();
        }
        if (!pq.empty())
        {
            ans = max(ans, a[i].second + pq.top().second);
        }
        else
        {
            if (a[i].first <= R)
            {
                ans = max(ans, a[i].second);
            }
        }
        pq.push(a[i]);
    }

    return ans;
}

int main()
{
    int N, R;
    cin >> N >> R;

    vector<int> P(N);
    vector<int> H(N);

    for (int i = 0; i < N; i++)
    {
        cin >> P[i];
    }
    for (int i = 0; i < N; i++)
    {
        cin >> H[i];
    }

    cout << maximumHealthiness(N, R, P, H) << endl;
}