#include <bits/stdc++.h>
using namespace std;
struct asdf{
int t, l, m; //time, location, money
bool operator < (asdf &rhs){
return t < rhs.t;
}
};
const int MAX_N = 1<<19;
struct SegTree {
int seg[MAX_N*2-1];
SegTree() {
for(int i=0; i<MAX_N*2-1; i++) seg[i] = -1e9;
}
int query(int a, int b, int k=0, int l=0, int r=MAX_N){
if (b <= l || r <=a)return -1e9;
if (a<=l&&r<=b) return seg[k];
return max(query(a,b,k*2+1,l,(l+r)/2), query(a,b,k*2+2,(l+r)/2,r));
}
void update(int k, int v) {
k += MAX_N-1;
seg[k] = v;
while (k > 0) {
k=(k-1)/2;
seg[k]=max(seg[k*2+1],seg[k*2+2]);
}
}
};
SegTree s1, s2;
vector<asdf> v;
int dp[505050];
int n, u, s, d;
void update(int i){
s1.update(v[i].l, dp[i] + d * v[i].l);
s2.update(v[i].l, dp[i] - u * v[i].l);
}
int get(int i){
int t1 = s1.query(0, v[i].l) - d*v[i].l + v[i].m;
int t2 = s2.query(v[i].l, 500000) + u*v[i].l + v[i].m;
return max(t1, t2);
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> u >> d >> s;
v.resize(n);
for(int i=0; i<n; i++){
cin >> v[i].t >> v[i].l >> v[i].m;
}
v.push_back({0, s, 0}); //시점
v.push_back({500010, s, 0}); //종점
sort(v.begin(), v.end());
dp[0] = 0;
update(0);
for(int i=1; i<=n+1; i++){
dp[i] = get(i);
update(i);
}
cout << dp[n+1];
}
