#include <bits/stdc++.h>
#ifdef LOCAL
#include <debug.hpp>
#else
#define debug(...) void(0)
#endif

template <class T> std::istream& operator>>(std::istream& is, std::vector<T>& v) {
    for (auto& e : v) {
        is >> e;
    }
    return is;
}

template <class T> std::ostream& operator<<(std::ostream& os, const std::vector<T>& v) {
    for (std::string_view sep = ""; const auto& e : v) {
        os << std::exchange(sep, " ") << e;
    }
    return os;
}

template <class T, class U = T> bool chmin(T& x, U&& y) {
    return y < x and (x = std::forward<U>(y), true);
}

template <class T, class U = T> bool chmax(T& x, U&& y) {
    return x < y and (x = std::forward<U>(y), true);
}

template <class T> void mkuni(std::vector<T>& v) {
    std::ranges::sort(v);
    auto result = std::ranges::unique(v);
    v.erase(result.begin(), result.end());
}

template <class T> int lwb(const std::vector<T>& v, const T& x) {
    return std::distance(v.begin(), std::ranges::lower_bound(v, x));
}

#include <atcoder/segtree>

using ll = long long;

using namespace std;

const int INF = 1 << 30;
const ll IINF = 1LL << 60;

ll op(ll l, ll r) { return max(l, r); }

ll e() { return -IINF; }

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);
    int N, S, H;
    cin >> N >> S >> H;
    vector<int> X(N), Y(N), Z(N);
    for (int i = 0; i < N; i++) cin >> X[i] >> Y[i] >> Z[i];

    vector<int> cand;
    cand.emplace_back(-INF);
    for (int i = 0; i < N; i++) {
        for (int d : {-H, 0, H}) {
            cand.emplace_back(X[i] + d);
            cand.emplace_back(Y[i] + d);
        }
    }
    mkuni(cand);
    int len = cand.size();
    map<int, int> mp;
    for (int i = 0; i < len; i++) mp[cand[i]] = i;
    vector<vector<int>> End(len);
    for (int i = 0; i < N; i++) {
        if (Y[i] - X[i] > S) continue;
        End[mp[Y[i]]].emplace_back(i);
    }
    atcoder::segtree<ll, op, e> seg1(len), seg2(len);
    seg1.set(0, 0);
    for (int i = 1, p = 0, q = 0; i < len; i++) {
        while (p < len and cand[p] < cand[i] - S) p++;
        while (q < len and cand[q] <= cand[i] - H) q++;
        for (int& idx : End[i]) {
            seg1.set(i, seg2.prod(p, i));
            seg1.set(i, seg2.prod(p, mp[X[idx]] + 1) + Z[idx]);
        }
        seg2.set(i, seg1.prod(0, q));
    }

    ll ans = max(seg1.all_prod(), seg2.all_prod());
    cout << ans << "\n";
    return 0;
}