#include<bits/stdc++.h>
#include<atcoder/segtree>
using namespace std;
using ll=long long;
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
template<class T> bool chmax(T &a, T b){if (a < b){a = b;return true;} else return false;}
template<class T> bool chmin(T &a, T b){if (a > b){a = b;return true;} else return false;}

const ll INF=1LL<<60;

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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N,S,H;
    cin>>N>>S>>H;
    vector<int>X(N),Y(N);
    vector<ll>Z(N);
    atcoder::segtree<ll,op,e>seg(N+1);
    seg.set(0,0);
    for(int i=0;i<N;i++)cin>>X[i]>>Y[i]>>Z[i];
    for(int i=0;i<N;i++){
        if(Y[i]-X[i]<=S){
            auto id=lower_bound(all(Y),X[i]-H+1);
            seg.set(i+1,seg.prod(0,id-Y.begin()+1)+Z[i]);
        }
    }
    ll ans=0;
    for(int i=0;i<=N;i++)chmax(ans,seg.get(i));
    cout<<ans<<"\n";
}