#include <bits/stdc++.h>
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
const ll ILL=2167167167167167167;
const int INF=2100000000;
const int mod=998244353;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,T b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
bool yneos(bool a,bool upp=0){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;}
template<class T> void vec_out(vector<T> &p,int ty=0){
if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;}
template<class T> bool inside(T l,T x,T r){return l<=x&&x<r;}

#include <atcoder/segtree>
ll op(ll a, ll b){
    return max(a, b);
}
ll e(){
    return 0;
}

void solve();
// CYAN / FREDERIC
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int t = 1;
    // cin >> t;
    rep(i, 0, t) solve();
}

void solve(){
    ll N, K;
    cin >> N >> K;
    vector<ll> T(N), X(N), C(N), A(N), B(N);
    rep(i, 0, N) cin >> T[i];
    rep(i, 0, N) cin >> X[i];
    rep(i, 0, N) cin >> C[i];
    rep(i, 0, N){
        A[i] = T[i] * K + X[i];
        B[i] = T[i] * K - X[i];
    }
    vector<int> order1(N), order2(N);
    rep(i, 0, N){
        order1[i] = i;
        order2[i] = i;
    }
    sort(all(order1), [&](int l, int r){
        if (A[l] == A[r]) return B[l] < B[r];
        return A[l] < A[r];
    });
    sort(all(order2), [&](int l, int r){
        if (B[l] == B[r]) return A[l] < A[r];
        return B[l] < B[r];
    });
    vector<int> inv(N);
    rep(i, 0, N) inv[order1[i]] = i;
    atcoder::segtree<ll, op, e> seg(N);
    rep(i, 0, N){
        int a = order2[i];
        if (B[a] < 0) continue;
        seg.set(inv[a], seg.prod(0, inv[a]) + C[a]);
    }
    cout << seg.all_prod() << "\n";
}