#include<bits/stdc++.h>
using namespace std;

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}
// defcomp
template <typename T>
vector<T> compress(vector<T> &X) {
	vector<T> vals = X;
	sort(vals.begin(), vals.end());
	vals.erase(unique(vals.begin(), vals.end()), vals.end());
	return vals;
}
// -----


// importbisect
template <typename T>
int bisect_left(vector<T> &X, T v){
	return lower_bound(X.begin(), X.end(), v) - X.begin();
}

template <typename T>
int bisect_right(vector<T> &X, T v){
	return upper_bound(X.begin(), X.end(), v) - X.begin();
}
// -----

ll op(ll a, ll b){
	return max(a, b);
}

ll e(){
	return -1e18;
}

int main(){
	int n; cin >> n;
	ll s, h; cin >> s >> h;
	vector<ll> x(n), y(n), z(n);
	rep(i,0,n){
		cin >> x[i] >> y[i] >> z[i];
	}

	vector<ll> dp(2*(n+1));
	segtree<ll,op,e> seg(n+1);
	vector<ll> rui(n+1);
	rep(i,0,n){
		rui[i+1] = rui[i] + z[i];
	}
	seg.set(0, 0);

	rep(i,1,n+1){
		chmax(dp[i], dp[i-1]);
		chmax(dp[n+1+i], dp[n+i]);

		int r = bisect_right(y, x[i-1]-h);
		if (r >= 0){
			chmax(dp[i-1], dp[n+1+r]);
		}
		seg.set(i-1, dp[i-1]-rui[i-1]);
	
		r = bisect_left(x, y[i-1]-s);
		chmax(dp[i+n+1], seg.prod(r, i) + rui[i]);
		//cout << r << ' ' << i << ' ' << dp[i] << endl;

	
	}

	cout << max(dp) << endl;
}