#include <bits/stdc++.h>
using namespace std;

#define int long long
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

const int inf = 3000ll*1000000000ll;
int n, V, l;
int x[2010];
int v[2010];
int w[2010];
int memo[2010][2010];

int dp(int i, int noko){
	if(noko < 0) return inf;
	if(i == n) return 0;
	if(memo[i][noko] != -1) return memo[i][noko];
	return memo[i][noko] = min(
		dp(i+1, noko-(x[i+1]-x[i])),
		dp(i+1, min(noko+v[i], V)-(x[i+1]-x[i]))+w[i]
	);
}

signed main(){
	cin >> n >> V >> l;

	for(int i = 0;i < n;i++){
		cin >> x[i] >> v[i] >> w[i];
	}
	x[n] = l;

	memset(memo, -1, sizeof(memo));

	int ans = dp(0, V-x[0]);

	if(ans < inf){
		cout << ans << endl;
	}else{
		cout << -1 << endl;
	}

	return 0;
}