#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	int N, V, L;
	cin >> N >> V >> L;
	vector<int> x(N + 2), v(N + 2), w(N + 2);
	FOR(i, 1, N + 1) scanf("%d %d %d", &x[i], &v[i], &w[i]);
	x[N + 1] = L;
	
	N += 2;
	vector dp(N + 1, vector(V + 1, longINF));
	dp[0][V] = 0;
	REP(i, N - 1) REP(j, V + 1) {
		if (dp[i][j] == longINF) continue;
		const int l = x[i + 1] - x[i];
		if (j >= l) {
			chmin(dp[i + 1][j - l], dp[i][j]);
			chmin(dp[i + 1][min(V, j - l + v[i + 1])], dp[i][j] + w[i + 1]);
		}
	}
	
	ll ans = *min_element(ALL(dp[N - 1]));
	if (ans == longINF) puts("-1");
	else cout << ans << endl;
}