#include <bits/stdc++.h>
#define loop(n) for (int ngtkana_is_genius = 0; ngtkana_is_genius < int(n); ngtkana_is_genius++)
#define rep(i, begin, end) for(int i = int(begin); i < int(end); i++)
#define all(v) v.begin(), v.end()
#define rand(l, r) std::uniform_int_distribution<>(l, r)(mt)
using lint = long long;
auto cmn = [](auto& a, auto b){if (a > b) {a = b; return true;} return false;};
auto cmx = [](auto& a, auto b){if (a < b) {a = b; return true;} return false;};

void err() { std::cout << -1 << std::endl; exit(0); }
#define require(exp) do { if (!(exp)) { err(); } } while(false)

int main() {
  std::cin.tie(0); std::cin.sync_with_stdio(false);
  int n, V, L;
  std::cin >> n >> V >> L;
  std::vector< int > x(n), v(n), w(n);
  rep(i, 0, n) {
    std::cin >> x.at(i) >> v.at(i) >> w.at(i);
  }
  x.push_back(L);
  v.push_back(0);
  w.push_back(0);

  // error
  if (V < x.front())
    { err(); }
  rep(i, 0, n) {
    if (V < x.at(i + 1) - x.at(i))
      { err(); }
  }

  constexpr lint linf = 1LL << 60;
  std::vector< lint > dp(V + L + 1, linf);
  dp.at(V) = 0;
  auto time = 0;
  rep(i, 0, n + 1) {
    auto s = x.at(i), t = s + V;
    for (auto j = t; j >= s; j--) {
      if (dp.at(j) == linf) continue;
      auto k = std::min(t, j + v.at(i));
      cmn(dp.at(k), dp.at(j) + w.at(i));
    }
  }
  auto ret = *std::min_element(dp.begin() + L, dp.end());
  if (ret == linf) err();
  std::cout << ret << std::endl;
  return 0;
}