#include <bits/stdc++.h>
using namespace std;
int main(void){
    int n,t;
    cin>>n>>t;
    vector<pair<pair<int,int>,int>>v;
    for(int i=0;i<n;i++){
        int l,r,p;
        cin>>l>>r>>p;
        v.push_back({{l,r},p});
    }
    sort(v.begin(), v.end());
    int maxv[200001]={};
    priority_queue<pair<int,int>>pq;
    int it=0;
    for(int i=0;i<200001;i++){
        while(1){
            if(it>=n)break;
            if(v[it].first.first==i){
                pq.push({v[it].second,v[it].first.second});
                it++;
            }else{
                break;
            }
        }
        while(1){
            if(pq.empty())break;
            if(pq.top().second<=i-1){
                pq.pop();
            }else{
                break;
            }
        }
        if(pq.empty())continue;
        maxv[i]=pq.top().first;
    }
    long long ans=0;
    long long dp[200001]={};
    for(int i=0;i<200001;i++){
        if(i!=0&&dp[i]<dp[i-1])dp[i]=dp[i-1];
        if(i+t>200000){
            if(ans<dp[i]+maxv[i])ans=dp[i]+maxv[i];
        }else{
            dp[i+t]=maxv[i]+dp[i];
        }
    }
    cout<<ans<<endl;
    return 0;
}