#include <cstdio>
#include <iostream>
#include <algorithm>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cmath>
#include <iomanip>
#include <cassert>
#include <bitset>
using namespace std;
typedef pair<int, int> P;
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(c) (c).begin(), (c).end()
#define uniq(c) c.erase(unique(all(c)), (c).end())
#define index(xs, x) (int)(lower_bound(all(xs), x) - xs.begin())
#define _1 first
#define _2 second
#define pb push_back
#define INF 1000141919
#define MOD 1000000007
#define MAX_N (1<<19)
struct SegTree {
int seg[MAX_N*2-1];
SegTree() {
rep(i, MAX_N*2-1) seg[i] = -INF;
}
int query(int a, int b, int k=0, int l=0,int r=MAX_N){
if (b <= l || r <=a)return -INF;
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 segL, segR;
int N, D, U, S;
vector<P> G[500000];
int dp[500001];
int tmp[500001];
void update(int x, int v) {
//if (dp[x] == v)return;
dp[x] = v;
segR.update(x, dp[x]+x*D);
segL.update(x, dp[x]-x*U);
}
signed main() {
ios::sync_with_stdio(false); cin.tie(0);
cin >> N >> D >> U >> S, S--;
rep(i, N) {
int time, pos, val;
cin >> time >> pos >> val;
pos--, time--;
G[time].pb(P(pos, val));
}
rep(i, 500001) dp[i] = -INF;
update(S, 0);
rep(t, 500000) {
if (G[t].empty()) continue;
sort(all(G[t]));
if (G[t].size() == 1) {
for (P p : G[t]) {
int x = p._1, val = p._2;
int e = val+max(segR.query(0, x+1)-x*D, segL.query(x, MAX_N)+x*U);
if (e > dp[x]) update(x, e);
}
}
else {
for (P p : G[t]) tmp[p._1] = dp[p._1];
for (P p : G[t]) {
int x = p._1, val = p._2;
int e = val+max(segR.query(0, x+1)-x*D, segL.query(x, MAX_N)+x*U);
if (e > dp[x]) update(x, e);
}
// rollback
for (P p : G[t]) swap(tmp[p._1], dp[p._1]), update(p._1, dp[p._1]);
reverse(all(G[t]));
for (P p : G[t]) {
int x = p._1, val = p._2;
int e = val+max(segR.query(0, x+1)-x*D, segL.query(x, MAX_N)+x*U);
if (e > dp[x]) update(x, e);
}
for (P p : G[t]) if (tmp[p._1] > dp[p._1]) update(p._1, tmp[p._1]);
}
}
int m = max(segR.query(0, S+1)-S*D, segL.query(S, MAX_N)+S*U);
cout << m << "\n";
return 0;
}
