#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<tuple>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = (ll)1000000007 * 1000000007;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define Per(i,sta,n) for(int i=n-1;i>=sta;i--)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
typedef long double ld;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;
int dx[4]={1,-1,0,0};
int dy[4]={0,0,1,-1};

int N,V,L;
int x[2010],v[2010];ll w[2010];
ll dp[2010][2010];

void solve(){
  cin >> N >> V >> L;
  rep(i,N){
    cin >> x[i+1] >> v[i+1] >> w[i+1];
  }
  x[N+1]=L;
  rep(i,N+2){
    rep(j,V+1){
      dp[i][j]=INF;
    }
  }
  dp[0][V]=0;
  rep(i,N+1){
    rep(j,V+1){
      if(x[i+1]-x[i]>j) continue;
      dp[i+1][min(V,j-x[i+1]+x[i]+v[i+1])]=min(dp[i+1][min(V,j-x[i+1]+x[i]+v[i+1])],dp[i][j]+w[i+1]);
      dp[i+1][j-x[i+1]+x[i]]=min(dp[i+1][j-x[i+1]+x[i]],dp[i][j]);
    }
  }
  ll ans=INF;
  rep(j,V+1){
    ans=min(ans,dp[N+1][j]);
  }
  // rep(i,N+2){
  //   rep(j,V+1){
  //     cout << i << " " << j << " " << dp[i][j] << endl;
  //   }
  // }
  if(ans<INF)cout << ans << endl;
  else cout << -1 << endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(50);
    solve();
}