#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
#define rep(i, s, t) for (ll i = s; i < (ll)(t); i++)

template<typename T>
bool chmin(T &x, T y) { return x > y ? (x = y, true) : false; }
template<typename T>
bool chmax(T &x, T y) { return x < y ? (x = y, true) : false; }

struct io_setup {
	io_setup() {
		ios::sync_with_stdio(false);
		std::cin.tie(nullptr);
		cout << fixed << setprecision(15);
	}
} io_setup;

// template atcoder segtree
using S = ll;
S op(S a, S b){
	return max(a, b);
}
S e(){
	return -1e18;
}
using segtree = atcoder::segtree<S,op,e>;

int main(){
	ll n,s,h;
	cin>>n>>s>>h;
	vector<ll> x(n),y(n),z(n);
	rep(i,0,n) cin>>x.at(i)>>y.at(i)>>z.at(i);
	vector<ll> sz(n+1);
	rep(i,0,n) sz.at(i+1)=sz.at(i)+z.at(i);
	segtree dp1(n+1),dp2(n+1);
	rep(i,0,n){
		if(y.at(i)-x.at(i)>s) continue;
		int mny=upper_bound(y.begin(),y.end(),x.at(i)-h)-y.begin();
		int mxx=lower_bound(x.begin(),x.end(),y.at(i)-s)-x.begin();
		if(0<mny) dp1.set(i,dp2.prod(0,mny)-sz.at(i));
		else dp1.set(i,-sz.at(i));
		if(mxx<i+1) dp2.set(i,dp1.prod(mxx,i+1)+sz.at(i+1));
		else dp2.set(i,sz.at(i+1));
	}
	cout<<dp2.all_prod()<<endl;
}