#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int inf=0x3f3f3f3f;
const int base=1<<19;
int N,D,U,S,dp[500010],Dtree[1<<20],Utree[1<<20];
struct market{ int T,L,M; }d[500010];
bool cmp(const market &p1,const market &p2){ return p1.T==p2.T?p1.L<p2.L:p1.T<p2.T; };
int query(int (&tree)[1<<20],int l,int r){
l+=base; r+=base;
int ret=-inf;
while(l<=r){
if(l&1) ret=max(ret,tree[l]);
if(~r&1) ret=max(ret,tree[r]);
l=(l+1)>>1; r=(r-1)>>1;
}
return ret;
}
void update(int (&tree)[1<<20],int p,int v){
p+=base-1;
while(p>>=1) tree[p]=max(tree[p],v);
}
/*
int query(int (&tree)[1<<20],int l,int r){
int ret=-inf;
for(;l<=r;l++) ret=max(ret,tree[l]);
return ret;
}
void update(int (&tree)[1<<20],int p,int v){
tree[p]=v;
}
*/
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>N>>D>>U>>S;
for(int i=1;i<=N;i++) cin>>d[i].T>>d[i].L>>d[i].M;
sort(d+1,d+N+1,cmp);
d[0]={0,S,0}; d[N+1]={500010,S,0};
for(int i=0;i<(1<<20);i++) Dtree[i]=Utree[i]=-inf;
update(Dtree,d[0].L,dp[0]-d[0].L*D);
update(Utree,d[0].L,dp[0]+d[0].L*U);
for(int i=1;i<=N+1;i++){
dp[i]=max(query(Dtree,d[i].L,500000)+d[i].L*D,query(Utree,0,d[i].L-1)-d[i].L*U)+d[i].M;
update(Dtree,d[i].L,dp[i]-d[i].L*D);
update(Utree,d[i].L,dp[i]+d[i].L*U);
}
cout<<dp[N+1];
return 0;
}
