#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define srep(i,s,t) for(int i=(int)(s);i<(int)(t);++i)
#define each(a,b) for(auto (a): (b))
#define all(v) (v).begin(),(v).end()
#define len(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define cmx(x,y) x=max(x,y)
#define cmn(x,y) x=min(x,y)
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define spair(p) cout<<#p<<": "<<p.fi<<" "<<p.se<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout<<" "<<kbrni;cout<<endl
#define smap(m) cout<<#m<<":";each(kbrni,m)cout<<" {"<<kbrni.first<<":"<<kbrni.second<<"}";cout<<endl

using namespace std;

typedef pair<int,int> P;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<P> vp;
typedef vector<string> vs;

const int MAX_N = 100005;

struct Edge{
    Edge(const short to,const short reverse,const char capacity,const int cost,bool is_reverse = false):to{to},reverse{reverse},capacity{capacity},flow{0},cost{cost},is_reverse{is_reverse}{}
    short to;
    short reverse;
    char capacity;
    char flow;
    int cost;
    bool is_reverse;
};

class tsort {
public:
	vector<int> deg;
    vector<short> order;
	short V;
	tsort(const vector<vector<Edge>>& g)
    {
		V = len(g);
		deg.resize(V,0);
        rep(i,len(g)){
            for(const Edge& e : g[i]){
                if(!e.is_reverse){
                    deg[e.to]++;
                }
            }
        }
        make(g);
	}
	void make(const vector<vector<Edge>>& G) {
		queue<short> que;
		rep(i,V){
	        if(deg[i] == 0){
	            que.push(i);
	        }
	    }
		while(!que.empty()){
			short p = que.front();
	        que.pop();
			order.push_back(p);
			rep(i,G[p].size()){
	            if(--deg[G[p][i].to] == 0){
	                que.push(G[p][i].to);
	            }
	        }
		}
	}
};

class CostFlow
{
public:
    using T = int;

    CostFlow(const short v):V{v}
    {
        edge.resize(v);
        m_dist.resize(v);
        m_potential.resize(v);
        m_prev_v.resize(v);
        m_prev_e.resize(v);
    }

    void addEdge(const short from, const short to, const char capacity,const T cost)
    {
        edge[from].pb(Edge{to,(short)edge[to].size(),capacity,cost,false});
        edge[to].pb(Edge{from,(short)(edge[from].size()-1),0,-cost,true});
    }

    T minCostFlow(const short s,const short t, char f)
    {
    //    const T INF = numeric_limits<T>::max()/100;
        using P = pair<T,short>;
        T res = 0;
        fill(all(m_potential),0);
        tsort ts(edge);
// potential
        for(short i =0; i < V; i++){
            m_potential[i] = INF;
        }
        m_potential[s] = 0;
//        assert(s == order[0]);
    //    svec(order);

        for(const short i:ts.order){
            if(m_potential[i] != INF){
                for(const auto& e: edge[i]){
                    if(e.is_reverse){
                        continue;
                    }
                    m_potential[e.to] = min(m_potential[e.to],m_potential[i]+e.cost);
                }
            }
        }

//        svec(m_potential);

        while(f > 0)
        {
            priority_queue<P,vector<P>,greater<P>> q;
            fill(all(m_dist),INF);
            m_dist[s]=0;
            q.push(make_pair(0,s));
            while(not q.empty()){
                const P p = q.top();
                q.pop();
                const short v = p.second;
                if(m_dist[v] < p.first){
                    continue;
                }
                for(short i = 0; i < edge[v].size();i++){
                    const auto& e = edge[v][i];
                    if(e.capacity > e.flow and m_dist[e.to] > m_dist[v]+e.cost+m_potential[v]-m_potential[e.to]){
                        m_dist[e.to] = m_dist[v]+e.cost+m_potential[v]-m_potential[e.to];
                        m_prev_v[e.to] = v;
                        m_prev_e[e.to] = i;
                        q.push(make_pair(m_dist[e.to],e.to));
                    }
                }
            }

            if(m_dist[t] == INF){
                return -1;
            }
            for(short v = 0; v < V; v++){
                m_potential[v] += m_dist[v];
            }
            char d = f;
            for(short v = t; v != s; v = m_prev_v[v]){
                const auto& e = edge[m_prev_v[v]][m_prev_e[v]];
                d = min(d,(char)(e.capacity-e.flow));
            }
            f-= d;
            res += d*m_potential[t];
            for(short v = t; v != s;v=m_prev_v[v]){
                auto& e = edge[m_prev_v[v]][m_prev_e[v]];
                e.flow += d;
                edge[v][e.reverse].flow-=d;
            }
        }
        return res;
    }

    const short V;
    vector<vector<Edge>> edge;
private:
    vector<T> m_dist;
    vector<T> m_potential;
    vector<short> m_prev_v;
    vector<short> m_prev_e;
};

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n,v,xr,xl;
    cin >> n >> v >> xr >> xl;
    vvl vec(n,vl(3));
    rep(i,n){
        rep(j,3){
            cin >> vec[i][j];
        }
    }
    CostFlow mc(2*n+4);
    rep(i,n){
        mc.addEdge(i,n+i,1,0);
    }
    rep(i,2){
        mc.addEdge(2*n,2*n+1+i,1,0);
    }
    rep(i,n){
        if(abs(xl-vec[i][0]) <= v*vec[i][1]){
            mc.addEdge(2*n+1,i,1,0);
        }
    }
    rep(i,n){
        if(abs(xr-vec[i][0]) <= v*vec[i][1]){
            mc.addEdge(2*n+2,i,1,0);
        }
    }
    rep(i,n){
        rep(j,n){
            if(i != j){
                if(abs(vec[i][0]-vec[j][0]) <= v*(vec[j][1]-vec[i][1])){
                    mc.addEdge(n+i,j,1,-vec[i][2]);
                }
            }
        }
    }
    rep(i,n){
        mc.addEdge(n+i,2*n+3,1,-vec[i][2]);
    }
    rep(i,2){
        mc.addEdge(2*n+1+i,2*n+3,1,0);
    }
    cout << -mc.minCostFlow(2*n,2*n+3,2) << "\n";
    return 0;
}

Measured memory_bytes: 241720