#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n) - 1; i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r) - 1;i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
template<class S, S op(S l, S r), S e()>
struct DualSegtree {
private:
	int mn = 0;
	int mN = 0;
	int mlogN = 0;
	std::vector<S> A;
	void propagate(int i) {
		if (i >= mN) return;
		A[i * 2] = op(A[i * 2], A[i]);
		A[i * 2 + 1] = op(A[i * 2 + 1], A[i]);
		A[i] = e();
	}
	void full_propagate(int i) {
		for (int d = mlogN; d > 0; d--) propagate(i >> d);
	}
public:
	DualSegtree(int n = 0) {
		mn = n;
		mlogN = 0; mN = 1;
		while (mN < n) { mN *= 2; mlogN++; }
		A.assign(mN * 2, e());
	}
	void point_init(int p) {
		assert(0 <= p); assert(p < mn);
		p += mN;
		full_propagate(p);
		A[p] = e();
	}
	S get(int p) {
		assert(0 <= p); assert(p < mn);
		p += mN;
		full_propagate(p);
		return A[p];
	}
	void apply(int l, int r, S x) {
		l += mN;
		r += mN;
		if (l != mN) full_propagate(l - 1);
		if (r != mN * 2) full_propagate(r);
		while (l < r) {
			if (l & 1) { A[l] = op(A[l], x); l++; }
			if (r & 1) { r--; A[r] = op(A[r], x); }
			l /= 2; r /= 2;
		}
	}
};
namespace RangeChangeMax {
	//区間chmin、一点取得
	using S = long long;
	S op(S x, S f) { return std::max(x, f); }
	S e() { return { 0 }; }
}
int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	int n, t; cin >> n >> t;
	DualSegtree<RangeChangeMax::S, RangeChangeMax::op, RangeChangeMax::e>seg(200005);
	rep(i, n) {
		int l, r, p; cin >> l >> r >> p;
		seg.apply(l, r + 1, p);
	}
	vector<long long> dp(200010);
	rep(i, 200005) {
		{
			int ni = i + 1;
			chmax(dp[ni], dp[i]);
		}
		{
			int ni = min(200010 - 1, i + t);
			int add = seg.get(i);
			chmax(dp[ni], dp[i] + add);
		}
	}
	long long ans = 0;
	for (auto e : dp)chmax(ans, e);
	cout << ans << endl;
	return 0;
}