#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> p;
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<p> v[505050];
vector<int> dpl[505050], dpr[505050];
int n, u, s, d;
void update(int i, int j){
s1.update(v[i][j].first, max(dpl[i][j], dpr[i][j]) + d * v[i][j].first);
s2.update(v[i][j].first, max(dpl[i][j], dpr[i][j]) - u * v[i][j].first);
}
int get1(int i, int j){
int ret = -1e9;
if(j-1 >= 0) ret = dpl[i][j-1] - d * (v[i][j].first - v[i][j-1].first) + v[i][j].second;
int t1 = s1.query(0, v[i][j].first) - d*v[i][j].first + v[i][j].second;
int t2 = s2.query(v[i][j].first, 500001) + u*v[i][j].first + v[i][j].second;
return max({ret, t1, t2});
}
int get2(int i, int j){
int ret = -1e9;
if(j+1 < v[i].size()) ret = dpr[i][j+1] - u * (v[i][j+1].first - v[i][j].first) + v[i][j].second;
int t1 = s1.query(0, v[i][j].first) - d*v[i][j].first + v[i][j].second;
int t2 = s2.query(v[i][j].first, 500001) + u*v[i][j].first + v[i][j].second;
return max({ret, t1, t2});
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> u >> d >> s;
for(int i=0; i<n; i++){
int a, b, c; cin >> a >> b >> c;
v[a].push_back({b, c});
}
v[0].push_back({s, 0});
v[500001].push_back({s, 0});
for(int i=0; i<=500001; i++){
dpl[i].resize(v[i].size()), dpr[i].resize(v[i].size());
sort(v[i].begin(), v[i].end());
}
dpl[0][0] = dpr[0][0] = 0;
update(0, 0);
for(int i=1; i<=n+1; i++){
for(int j=0; j<v[i].size(); j++){
dpl[i][j] = get1(i, j);
dpr[i][j] = get2(i, j);
}
for(int j=0; j<v[i].size(); j++){
update(i, j);
}
}
cout << max(dpl[n+1][0], dpr[n+1][0]);
}
