#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> P;
typedef pair<ll,ll> l_l;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
#define pb push_back
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
const int INF=1001001000;
const int mINF=-1001001000;
const ll LINF=1010010010010010000;
template<class T> inline bool chmin(T& a, T b) {
if (a > b) {
a = b;
return true;
}
return false;
}
template<class T> inline bool chmax(T& a, T b) {
if (a < b) {
a = b;
return true;
}
return false;
}
//グリッド：（典型）dp,dfs,bfs,最短経路,その他
int main(){
    ll n,V,l;cin>>n>>V>>l;
    vl x(n),v(n),w(n);rep(i,n)cin>>x[i]>>v[i]>>w[i];
    vector<vl> dp(n+2,vl(V+1,LINF));
    dp[0][V]=0;
    ll d;
    rep(i,n+1){
        if(i==0)d=x[i];
        else if(i==n)d=l-x[i-1];
        else d=x[i]-x[i-1];
        rep(j,V+1){
            if(dp[i][j]!=LINF&&j>=d){
                chmin(dp[i+1][min(V,j-d+v[i])],dp[i][j]+w[i]);
                chmin(dp[i+1][j-d],dp[i][j]);
            }
        }
    }
    ll ans=LINF;
    rep(i,V+1)chmin(ans,dp[n+1][i]);
    if(ans==LINF){
        cout<<-1<<endl;
        return 0;
    }
    cout<<ans<<endl;
    return 0;
}