#include <bits/stdc++.h>
using namespace std;
using ll=long long;
int main(){
	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<ll> v(3e5);
	{
		vector<pair<int,ll>> evs,evs2;
		for(int i=0;i<n;i++){
			evs.push_back(make_pair(l[i],p[i]));
			evs2.push_back(make_pair(r[i]+1,-p[i]));
		}
		ranges::sort(evs);
		ranges::sort(evs2);
		multiset<ll> s;
		int idx=0,idx2=0;
		for(int i=0;i<3e5;i++){
			while(idx<n&&evs[idx].first==i){
				s.insert(evs[idx].second);
				idx++;
			}
			while(idx2<n&&evs2[idx2].first==i){
				s.erase(s.find(-evs2[idx2].second));
				idx2++;
			}
			if(!s.empty())v[i]=*(--s.end());
		}
	}
	vector<ll> dp(3e5);
	for(int i=0;i<3e5;i++){
		if(i+1<3e5)dp[i+1]=max(dp[i+1],dp[i]);
		if(i+t<3e5)dp[i+t]=max(dp[i+t],dp[i]+v[i]);
	}
	cout<<dp[3e5-1]<<endl;
}