#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int(i) = 0; (i) < (n); (i)++)
#define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++)
#define All(v) (v).begin(), (v).end()
#define pb push_back
#define MP(a, b) make_pair((a), (b))
template <class T> vector<T> make_vec(size_t a, T val) {
    return vector<T>(a, val);
}
template <class... Ts> auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec(ts...))>(a, make_vec(ts...));
}
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using Graph = vector<vector<int>>;
template <typename T> struct edge {
    int to;
    T cost;
    edge(int t, T c) : to(t), cost(c) {}
};
template <typename T> using WGraph = vector<vector<edge<T>>>;
const int INF = 1 << 30;
const ll LINF = 1LL << 60;
const int MOD = 1e9 + 7;

int main() {
    ll N, V, L;
    cin >> N >> V >> L;
    vector<ll> x(N + 2), v(N + 2), w(N + 2);
    x[0] = 0;
    v[0] = 0;
    w[0] = 0;
    int last = 0;
    rep(i, N) { cin >> x[i + 1] >> v[i + 1] >> w[i + 1]; }
    x[N + 1] = L;
    v[N + 1] = 0;
    w[N + 1] = 0;
    N = N + 2;
    auto dp = make_vec(N + 1, V + 1, (ll)INF);
    dp[0][V] = 0;
    // dp[i][j]:=iにいてガソリンがjのときの費用
    for(int i = 0; i < N - 1; i++) {
        int cost = x[i + 1] - x[i];
        for(int j = V; j >= 0; j--) {
            if(j - cost >= 0)
                dp[i + 1][j - cost] = min(dp[i + 1][j - cost], dp[i][j]);
        }
        for(int j = V; j >= 0; j--) {
            dp[i + 1][min(V, j + v[i + 1])] =
                min(dp[i + 1][min(V, j + v[i + 1])], dp[i + 1][j] + w[i + 1]);
        }
        for(int j = V - 1; j >= 0; j--) {
            dp[i + 1][j] = min(dp[i + 1][j], dp[i + 1][j + 1]);
        }
    }
    ll res = INF;
    rep(i, V + 1) { res = min(res, dp[N - 1][i]); }
    cout << (res == INF ? -1 : res) << endl;
}