#ifndef Yamada
#define Yamada
#include Yamada __FILE__ Yamada

const int B = 36;
const int maxc = 1 << 18;

set<pii> st[B];
int taw[B], tav[B];
int ans[maxc];

void solve() {
    int n, t; cin >> n >> t;
    vector<int> w(n), v(n);
    for (auto &x : w) cin >> x;
    for (auto &x : v) cin >> x;

    int idx = 0;
    /*
    for (int i = 9; i <= 9; ++i, ++idx) {
        int hb = __lg(i);
        st[hb].ee(i, idx);
    }
    */
    for (int i = max(int(1), t - maxc); i <= t; ++i, ++idx) {
        int hb = __lg(i);
        st[hb].ee(i, idx);
    }

    for (int i = 0; i < n; ++i) {
        int hb = __lg(w[i]);
        while (SZ(st[hb])) {
            auto it = st[hb].end(); it = prev(it);
            pii cur = *it;
            int c = cur.X - taw[hb];
            if (c < w[i]) break;

            ans[cur.Y] += tav[hb] + v[i];

            if (c > w[i]) {
                int nxtb = __lg(c - w[i]);
                ans[cur.Y] -= tav[nxtb];
                st[nxtb].ee(c - w[i] + taw[nxtb], cur.Y);
            }
            st[hb].erase(cur);
        }
        if (!SZ(st[hb])) taw[hb] = tav[hb] = 0;

        for (int j = hb + 1; j < B; ++j) {
            if (SZ(st[j])) {
                taw[j] += w[i], tav[j] += v[i];
            }
            while (SZ(st[j])) {
                pii cur = *st[j].begin();
                int c = cur.X - taw[j];
                int nxtb = __lg(c);

                if (nxtb == j) break;
                st[j].erase(cur);
                ans[cur.Y] += tav[j] - tav[nxtb];
                st[nxtb].ee(c + taw[nxtb], cur.Y);
            }
            if (!SZ(st[j])) taw[j] = tav[j] = 0;
        }
    }

    for (int i = 0; i < B; ++i) {
        for (auto it : st[i]) {
            ans[it.Y] += tav[i];
            // debug(__lg(it.X - taw[i]), i, it.X, it.Y);
            // assert(it.X - taw[i] >= 0 && __lg(it.X - taw[i]) == i);
        }
    }
    int tot = 0;
    for (int i = 0; i < idx; ++i) chmax(tot, ans[i]);
    print(tot);
}

signed main() {
    IOS();
    int t = 1; // cin >> t;
    for (int i=1;i<=t;++i) solve();
    return 0;
}

#else

#ifdef local 
#define _GLIBCXX_DEBUG 1
#endif
#pragma GCC optimize ("Ofast", "unroll-loops")
#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define double __float80
using pii = pair<int, int>;
template <typename T> using MaxHeap = std::priority_queue<T>;
template <typename T> using MinHeap = std::priority_queue<T, vector<T>, greater<T>>;

#define SZ(a) ((int)(a).size())
#define ALL(a) begin(a), end(a)
#define RALL(a) rbegin(a), rend(a)
#define ee emplace
#define eb emplace_back
#define ef emplace_front
#define pb pop_back
#define pf pop_front
#define X first
#define Y second

#ifdef local
#define IOS() void()
#define debug(...) \
    fprintf(stderr, "\e[1;93m"), \
    fprintf(stderr, "At [%s], line %d: (%s) = ", __FUNCTION__, __LINE__, #__VA_ARGS__), \
    _do(__VA_ARGS__), \
    fprintf(stderr, "\e[0m")
template <typename T> void _do(T &&_t) {cerr << _t << '\n';}
template <typename T, typename ...U> void _do(T &&_t, U &&..._u) {cerr << _t << ", ", _do(_u...);}
#define print(...) \
    fprintf(stderr, "\e[1;96m"), \
    _P(__VA_ARGS__), \
    fprintf(stderr, "\e[0m")
#else
#define IOS() ios_base::sync_with_stdio(0); cin.tie(0)
#define debug(...) void()
#define print(...) _P(__VA_ARGS__)
#define endl '\n'
#endif

template <typename U, typename V> bool chmin(U &u, V v) {return u > v ? u = v, 1 : 0;}
template <typename U, typename V> bool chmax(U &u, V v) {return u < v ? u = v, 1 : 0;}

template <typename T> void _P(T &&_x) {cout << _x << '\n';}
template <typename T, typename ...S> void _P(T &&_x, S &&..._t) {cout << _x << " "; _P(_t...);}

#endif