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

typedef long long ll;
const int N = 101010;
int n, w[N], v[N]; ll t;

int main() {
    cin.tie(0); ios_base::sync_with_stdio(0);
    cin >> n >> t;
    for (int i = 1; i <= n; i++) cin >> w[i];
    for (int i = 1; i <= n; i++) cin >> v[i];
    ll ans = 0;
    vector<pair<ll, ll>> s[2];
    s[0].push_back({ t, 0 });
    for (int i = 1; i <= n; i++) {
        s[i & 1].clear();
        auto [x, y] = s[~i & 1].back();
        if (x > 2 * N) {
            s[i & 1].push_back({ x - w[i], y + v[i] });
        }
        else {
            for (auto [x, y] : s[~i & 1]) {
                if (x == 0) {
                    ans = max(ans, y);
                }
                else if (w[i] > x) {
                    s[i & 1].push_back({ x, y });
                }
                else {
                    s[i & 1].push_back({ x - w[i], y + v[i] });
                    s[i & 1].push_back({ w[i] - 1, y });
                }
            }
            sort(s[i & 1].begin(), s[i & 1].end());
            s[i & 1].erase(unique(s[i & 1].begin(), s[i & 1].end()), s[i & 1].end());
        }
    }
    for (auto [x, y] : s[n & 1]) {
        ans = max(ans, y);
    }
    cout << ans;
}