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

int main(void) {
    int N, T; cin >> N >> T;
    vector<int> L(N), R(N);
    vector<ll> P(N);
    for (int i = 0; i < N; i++) {
        cin >> L[i] >> R[i] >> P[i];
    }

    vector<vector<ll>> add(200009), rem(200009);
    for (int i = 0;i < N;i++) {
        add[L[i]].push_back(P[i]);
        rem[R[i] + 1].push_back(P[i]);
    }

    multiset<ll> s;
    vector<ll> mx;
    for (int i = 0;i <= 200000;i++) {
        for (auto v : add[i])s.insert(v);
        if (s.empty())mx.push_back(0);
        else mx.push_back(*s.rbegin());
        for (ll v : rem[i]) {
            auto it = s.find(v);
            if (it != s.end())s.erase(it);
        }
    }
    vector<ll> dp(400009, -(1LL << 60));
    dp[0] = 0;
    int rmx = *max_element(R.begin(), R.end());
    for (int i = 0; i <= 200000; i++) {
        if (i <= rmx)dp[i + T] = max(dp[i + T], dp[i] + mx[i]);
        dp[i + 1] = max(dp[i + 1], dp[i]);
    }
    ll ans = *max_element(dp.begin(), dp.end());
    cout << ans << "\n";
}