#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

template <class T, class Comp = less<T>>
struct erasable_priority_queue {
  priority_queue<T, vector<T>, Comp> q, q_erase;
  void push(T x) { q.push(move(x)); }
  template <class... Args>
  void emplace(Args&&... args) {
    q.emplace(forward<Args>(args)...);
  }
  void erase(T x) { q_erase.push(move(x)); }
  decltype(auto) top() {
    assert(!empty());
    expose_top();
    return q.top();
  }
  void pop() {
    assert(!empty());
    expose_top();
    q.pop();
  }
  int size() { return int(q.size()) - int(q_erase.size()); }
  bool empty() { return !size(); }
  void expose_top() {
    while (!q_erase.empty() && q_erase.top() == q.top()) {
      q_erase.pop();
      q.pop();
    }
  }
};


} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, s, h;
  cin >> n >> s >> h;
  struct S {
    int x, y, z;
  };
  vector<S> d(n);
  for (auto& [x, y, z] : d) cin >> x >> y >> z;
  VL z_acc(n + 1);
  rep(i, n) z_acc[i+1] = z_acc[i] + d[i].z;
  constexpr int INF = 1001001001;
  d.emplace_back(2 * INF, 2 * INF, 0);
  VL dp(n + 1);
  int ptr1 = 0, ptr2 = 0;
  erasable_priority_queue<ll> q;
  rep(i, n) {
    chmax(dp[i+1], dp[i]);
    q.emplace(dp[i] - z_acc[i]);
    while (d[i].y - d[ptr1].x > s) {
      q.erase(dp[ptr1] - z_acc[ptr1]);
      ptr1++;
    }
    if (!q.empty()) {
      while (d[ptr2].x - d[i].y < h) ptr2++;
      chmax(dp[ptr2], q.top() + z_acc[i+1]);
    }
  }
  cout << dp[n] << '\n';
}