#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 1000000000000000001
int main(){

	long long N,S,H;
	cin>>N>>S>>H;
	
	vector<long long> x,y,z;
	rep(i,N){
		long long a,b,c;
		cin>>a>>b>>c;
		x.push_back(a);
		y.push_back(b);
		z.push_back(c);
	}
	N = x.size();
	x.push_back(Inf64);
	y.push_back(Inf64);
	z.push_back(0);
	N++;
	z.insert(z.begin(),0);
	rep(i,N)z[i+1] += z[i];
	
	mcf_graph<long long,long long> G(N*2);
	
	rep(i,N){
		if(i!=N-1){
			G.add_edge(i,i+1,1,z[i+1]-z[i]);
		}
		{
			long long nxt = x[i] + S;
			int d = distance(y.begin(),upper_bound(y.begin(),y.end(),nxt));
			d--;
			if(d!=-1)G.add_edge(i,N+d,1,0);
		}
		if(i!=0){
			G.add_edge(N+i,N+i-1,1,z[i+1]-z[i]);
		}
		{
			long long nxt = y[i] + H;
			int d = distance(x.begin(),upper_bound(x.begin(),x.end(),nxt));
			if(d!=N)G.add_edge(N+i,d,1,z[d] - z[i+1]);
		}
	}
	long long ans = G.flow(0,N-1,1).second;
	cout<<z.back() - ans<<endl;
	return 0;
}