#include <stdio.h>
#include <algorithm>
using namespace std;
struct Fair
{
int t,x,Value;
int id;
int i;
int Best;
int CurBest;
int LowBest;
inline bool operator < (const Fair &b) const
{
if(t<b.t) return true;
if(t==b.t && x<b.x) return true;
return false;
}
} Fairs[500040];
bool Compare1(Fair a, Fair b)
{
if(a.x<b.x) return true;
return false;
}
const int Max_N=1<<19;
const int inf=1000000000;
int SegmentTree[2][Max_N*2+20];
int max(int a, int b)
{
if(a>b) return a;
else return b;
}
void Initialize(int st)
{
int i;
for(i=0;i<Max_N*2+5;i++)
SegmentTree[st][i]=-inf;
}
void Set(int st, int index, int value)
{
int x=Max_N+index;
SegmentTree[st][x]=value;
x/=2;
while(x>0)
{
SegmentTree[st][x]=max(SegmentTree[st][x*2],SegmentTree[st][x*2+1]);
x/=2;
}
}
int Get(int st, int ss, int se, int si, int qs, int qe)
{
if(ss>qe || se<qs) return -inf;
if(ss>=qs && se<=qe) return SegmentTree[st][si];
int mid=(ss+se)>>1;
return max(Get(st,ss,mid,si*2,qs,qe),Get(st,mid+1,se,si*2+1,qs,qe));
}
int Get(int st, int qs, int qe)
{
return Get(st,0,Max_N-1,1,qs,qe);
}
int main()
{
int n,u,d,s,i,j;
scanf("%i %i %i %i",&n,&u,&d,&s);
Fairs[0].t=-1;
Fairs[0].x=s;
Fairs[0].Value=0;
Fairs[0].i=0;
int maxt=0;
for(i=1;i<=n;i++)
{
scanf("%i %i %i",&Fairs[i].t,&Fairs[i].x,&Fairs[i].Value);
maxt=max(maxt,Fairs[i].t);
Fairs[i].i=1;
}
Fairs[n+1].t=maxt+1;
Fairs[n+1].x=s;
Fairs[n+1].Value=0;
Fairs[n+1].i=n+1;
n+=2;
sort(Fairs,Fairs+n,Compare1);
for(i=0;i<n;i++)
{
Fairs[i].id=i;
}
sort(Fairs,Fairs+n);
Initialize(0);
Initialize(1);
Set(0,Fairs[0].id,d*Fairs[0].x);
Set(1,Fairs[0].id,-u*Fairs[0].x);
for(i=1;i<n;i++)
{
if(Fairs[i].t!=Fairs[i+1].t)
{
Fairs[i].Best=max(Get(0,0,Fairs[i].id-1)-d*Fairs[i].x,
Get(1,Fairs[i].id+1,n)+u*Fairs[i].x)+Fairs[i].Value;
Set(0,Fairs[i].id,Fairs[i].Best+d*Fairs[i].x);
Set(1,Fairs[i].id,Fairs[i].Best-u*Fairs[i].x);
}
else
{
int first=i;
int last;
while(Fairs[i].t==Fairs[i+1].t)
i++;
last=i;
for(j=first;j<=last;j++)
{
Fairs[j].LowBest=max(Get(0,0,Fairs[j].id-1)-d*Fairs[j].x,
Get(1,Fairs[j].id+1,n)+u*Fairs[j].x)+Fairs[j].Value;
Fairs[j].Best=Fairs[j].LowBest;
}
Fairs[first].CurBest=Fairs[first].LowBest;
Fairs[first].Best=Fairs[first].CurBest;
for(j=first+1;j<=last;j++)
{
int val=Fairs[j-1].CurBest-(Fairs[j].x-Fairs[j-1].x)*d+Fairs[j].Value;
Fairs[j].CurBest=max(val,Fairs[j].LowBest);
Fairs[j].Best=max(Fairs[j].Best,Fairs[j].CurBest);
}
Fairs[last].CurBest=Fairs[last].LowBest;
Fairs[last].Best=max(Fairs[last].Best,Fairs[last].CurBest);
for(j=last-1;j>=first;j--)
{
int val=Fairs[j+1].CurBest-(Fairs[j+1].x-Fairs[j].x)*u+Fairs[j].Value;
Fairs[j].CurBest=max(val,Fairs[j].LowBest);
Fairs[j].Best=max(Fairs[j].Best,Fairs[j].CurBest);
}
for(j=first;j<=last;j++)
{
Set(0,Fairs[j].id,Fairs[j].Best+d*Fairs[j].x);
Set(1,Fairs[j].id,Fairs[j].Best-u*Fairs[j].x);
}
}
}
if(Fairs[n-1].Best<0) printf("0\n");
else printf("%i\n",Fairs[n-1].Best);
return 0;
}
