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

int main() {
    constexpr int64_t inf = 1e18;
    int n, vmax, l;
    cin >> n >> vmax >> l;
    vector<int> x(n + 2), v(n + 2), w(n + 2);
    for (int i = 0; i < n; i++) {
        cin >> x.at(i + 1) >> v.at(i + 1) >> w.at(i + 1);
    }
    x.at(n + 1) = l;
    vector<vector<int64_t>> dp(n + 2, vector<int64_t>(vmax + 1, inf)); // remaining, cost
    dp.at(0).at(vmax) = 0;
    for (int i = 0; i <= n; i++) {
        int used = x.at(i + 1) - x.at(i);
        for (int j = 0; j <= vmax; j++) {
            int prev_j = j + used, prev_j_stop = max(0, prev_j - v.at(i + 1));
            if (prev_j <= vmax) {
                dp.at(i + 1).at(j) = min(dp.at(i + 1).at(j), dp.at(i).at(prev_j));
            }
            if (prev_j_stop <= vmax) {
                dp.at(i + 1).at(j) = min(dp.at(i + 1).at(j), dp.at(i).at(prev_j_stop) + w.at(i + 1));
            }
        }
    }
    int64_t ans = inf;
    for (int i = 0; i <= vmax; i++) {
        ans = min(ans, dp.at(n + 1).at(i));
    }
    if (ans == inf) {
        cout << -1 << endl;
    } else {
        cout << ans << endl;
    }
}