#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define INF 1000000000
#define mod 1000000007
using ll=long long;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

template<typename Monoid>
struct SegmentTree{
    using F=function<Monoid(Monoid,Monoid)>;
    int sz;
    vector<Monoid> seg;
    const F f;
    const Monoid gen;
    SegmentTree(int n,const F f,const Monoid &gen):f(f),gen(gen){
        sz=1;
        while(sz<n)sz<<=1;
        seg.assign(2*sz,gen);
    }
    void set(int k,const Monoid &x){
        seg[k+sz]=x;
    }
    void build(){
        for(int k=sz-1;k>0;k--) seg[k]=f(seg[2*k],seg[2*k+1]);
    }
    void update(int k,const Monoid &x){
        k+=sz;
        seg[k]=x;
        while(k>>=1) seg[k]=f(seg[2*k],seg[2*k+1]);
    }
   // [a,b)
    Monoid query(int a,int b){
        Monoid L=gen,R=gen;
        for(a+=sz,b+=sz;a<b;a>>=1,b>>=1){
            if(a&1) L=f(L,seg[a++]);
            if(b&1) R=f(seg[--b],R);
        }
        return f(L,R);
    }
    Monoid operator[](const int &k)const {
       return seg[k+sz];
    }
};
ll f(ll a,ll b){
    return (a<b?a:b);
}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    // dp[i][j]: i番目まで，燃料jの最小コスト
    
    ll N,V,L;cin>>N>>V>>L;

    ll dp[N+2][V+1];
    rep(i,N+2)rep(j,V+1)dp[i][j]=LINF;

    dp[0][V]=0;

    ll pre=0;
    rep(i,N){
        ll x,v,w;cin>>x>>v>>w;
        ll dis=x-pre;
        for(int j=0;j+dis<=V;j++){
            dp[i+1][j]=dp[i][j+dis];
        }

        SegmentTree<ll> seg(V+1,f,LINF);
        rep(j,V+1) seg.set(j,dp[i+1][j]);
        seg.build();
        for(int j=V;j>=0;j--){
            chmin(dp[i+1][j],seg.query(max(0ll,j-v),j)+w);
        }

        pre=x;
    }

    ll ans=LINF;
    ll dis=L-pre;
    for(int i=0;i+dis<=V;i++){
        dp[N+1][i]=dp[N][i+dis];
    }
    rep(i,V+1) chmin(ans,dp[N+1][i]);
    cout<<(ans<LINF?ans:-1)<<endl;
    return 0;
}