#include <bits/stdc++.h>
#define rep(i,n)for(int i=0;i<n;i++)
using namespace std;
typedef pair<int,int>P;
typedef long long ll;

const int MOD=1000000007;
const int INF=0x3f3f3f3f;
const ll INFL=0x3f3f3f3f3f3f3f3f;

ll dp[3000][3000];
ll x[3000],v[3000],w[3000];

int main(){
	ll n,V,L;cin>>n>>V>>L;
	rep(i,n){
		scanf("%lld%lld%lld",&x[i],&v[i],&w[i]);
	}
	x[n]=L;
	if(V<x[0]){
		puts("-1");return 0;
	}
	memset(dp,0x3f,sizeof(dp));
	dp[0][V-x[0]]=0;
	rep(i,n)rep(j,V+1){
		if(dp[i][j]==INFL)continue;
		ll cost=x[i+1]-x[i];
		if(j>=cost)dp[i+1][j-cost]=min(dp[i+1][j-cost],dp[i][j]);
		if(int nj=min(V,j+v[i]);nj>=cost)dp[i+1][nj-cost]=min(dp[i+1][nj-cost],dp[i][j]+w[i]);
	}
	ll Min=INFL;
	for(int i=0;i<=V;i++){
		Min=min(Min,dp[n][i]);
	}
	if(Min==INFL)puts("-1");
	else cout<<Min<<endl;
}