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

template <typename X>
struct SegTree{
    using FX = function<X(X, X)>; // X•X -> X となる関数の型
    int n;
    FX fx;
    const X ex;
    vector<X> dat;

    SegTree(int n_, const FX &fx_, const X &ex_) : n(), fx(fx_), ex(ex_){
        int x = 1;
        while(n_ > x){
            x *= 2;
        }
        n = x;
        dat.assign(n * 2, ex);
    }

    X get(int i) const {
        return dat[i + n];
    }

    void set(int i, const X &x){ dat[i + n] = x; }

    void build(){
        for(int k = n - 1; k >= 1; k--) dat[k] = fx(dat[k * 2], dat[k * 2 + 1]);
    }

    void update(int i, const X &x){
        i += n;
        dat[i] = x;
        while(i > 0){
            i >>= 1;  // parent
            dat[i] = fx(dat[i * 2], dat[i * 2 + 1]);
        }
    }

    X query(int a, int b){
        X vl = ex;
        X vr = ex;
        int l = a + n;
        int r = b + n;
        while(l < r){
            if(l & 1) vl = fx(vl, dat[l++]);
            if(r & 1) vr = fx(dat[--r], vr);
            l >>= 1;
            r >>= 1;
        }
        return fx(vl, vr);
    }

    X operator [](int i) const {
        return dat[i + n];
    }
};

template <typename T>
struct compress{
    vector<T> sorted;
    vector<int> compressed;

    compress(const vector<T> &vec){
        int n = vec.size();
        compressed.resize(n);
        for(T x : vec){
            sorted.emplace_back(x);
        }
        sort(sorted.begin(), sorted.end());
        sorted.erase(unique(sorted.begin(), sorted.end()), sorted.end());
        for(int i = 0; i < n; ++i){
            compressed[i] = lower_bound(sorted.begin(), sorted.end(), vec[i]) - sorted.begin();
        }
    }

    int get(const T &x) const{
        return lower_bound(sorted.begin(), sorted.end(), x) - sorted.begin();
    }

    T inv(const int x) const{
        return sorted[x];
    }

    size_t size() const{
        return sorted.size();
    }

    vector<T> getCompressed() const{
        return compressed;
    }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    long long k;
    cin >> n >> k;
    assert(n >= 1 && n <= 200000);
    assert(k >= 1 && k <= 1000000000LL);
    vector<long long> t(n), x(n), c(n);
    for(int i = 0; i < n; i++){
        cin >> t[i];
        assert(t[i] >= 1 && t[i] <= 1000000000LL);
    }
    for(int i = 0; i < n; i++){
        cin >> x[i];
        assert(abs(x[i]) <= 1000000000LL);
    }
    for(int i = 0; i < n; i++){
        cin >> c[i];
        assert(c[i] >= 1 && c[i] <= 1000000000LL);
    }

    set<pair<long long, long long>> s;
    for(int i = 0; i < n; i++){
        s.emplace(t[i], x[i]);
    }
    assert((int) s.size() == n);

    vector<long long> a(n), b(n);
    for(int i = 0; i < n; i++){
        a[i] = k * t[i] + x[i];
        b[i] = k * t[i] - x[i];
    }

    compress<long long> compa(a), compb(b);
    int sizea = compa.size(), sizeb = compb.size();

    SegTree<long long> seg(sizea, [](long long a, long long b){ return max(a, b); }, 0);
    vector<vector<pair<long long, long long>>> v(sizeb);
    for(int i = 0; i < n; i++){
        v[compb.get(b[i])].emplace_back(compa.get(a[i]), c[i]);
    }
    for(int i = 0; i < sizeb; i++){
        sort(v[i].begin(), v[i].end());
    }
    for(int i = 0; i < sizeb; i++){
        for(auto [a, c] : v[i]){
            long long val = seg.query(0, a + 1);
            seg.update(a, val + c);
        }
    }
    cout << seg.query(0, sizea) << "\n";
}