#include "bits/stdc++.h"
using namespace std;
#define int long long
#define REP(i, n) for (int i = 0; i < (int)n; ++i)
#define RREP(i, n) for (int i = (int)n - 1; i >= 0; --i)
#define FOR(i, s, n) for (int i = s; i < (int)n; ++i)
#define RFOR(i, s, n) for (int i = (int)n - 1; i >= s; --i)
#define ALL(a) a.begin(), a.end()
#define IN(a, x, b) (a <= x && x < b)
template<class T>inline void out(T t){cout << t << "\n";}
template<class T,class... Ts>inline void out(T t,Ts... ts){cout << t << " ";out(ts...);}
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;}
constexpr int INF = 1e18;



signed main(){
	int N,V,L;
	cin >> N >> V >> L;
	vector<tuple<int,int,int>>vec(N + 2);
	vec[0] = {0,0,0};
	FOR(i,1,N + 1){
		int a,b,c;
		cin >> a >> b >> c;
		vec[i] = {a,b,c};
	}
	vec[vec.size() - 1] = {L,0,0};
	vector<int>dp(L + 1,INF);
	dp[V] = 0;
	REP(i,vec.size() - 1){
		vector<int>ndp(L + 1,INF);
		auto[from,v,w] = vec[i];
		auto[to,hoge,huga] = vec[i + 1];
		auto dist = to - from;
		REP(j,L + 1){
			if(dp[j] == INF)continue;
			if(min(V,j + v) >= dist){
				CHMIN(ndp[min(V,j + v) - dist],dp[j] + w);
			}
			if(j >= dist){
				CHMIN(ndp[j - dist],dp[j]);
			}
		}
		dp = ndp;
	}
	int ans = *min_element(ALL(dp));
	if(ans == INF)cout << -1 << endl;
	else cout << ans << endl;
}