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

#ifdef LOCAL
#include "debug.h"
#else
#define DEBUG(...)
#endif

template <class T> constexpr T inf = numeric_limits<T>::max() / 2.1;

auto chmin = [](auto&& a, auto b) { return b < a ? a = b, 1 : 0; };

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int n, m, l;
  cin >> n >> m >> l;
  vector<int> x{0}, v{m}, w{0};
  for (int i = 0; i < n; ++i) {
    int xi, vi, wi;
    cin >> xi >> vi >> wi;
    if (xi == 0 or xi == l) {
      continue;
    }
    x.push_back(xi);
    v.push_back(vi);
    w.push_back(wi);
  }
  n = size(x);
  DEBUG(x);
  x.push_back(l);
  vector dp(n + 1, vector(m + 1, inf<long long>));
  fill(begin(dp[n]), end(dp[n]), 0);
  for (int i = n; i--; ) {
    for (int r = 0; r <= m; ++r) {
      if (x[i + 1] - x[i] <= r) {
        chmin(dp[i][r], dp[i + 1][r - (x[i + 1] - x[i])]);
      }
      if (int nr = min(r + v[i], m) - (x[i + 1] - x[i]); nr >= 0) {
        chmin(dp[i][r], w[i] + dp[i + 1][nr]);
      }
    }
  }
  if (dp[0][m] >= inf<long long>) {
    dp[0][m] = -1;
  }
  cout << dp[0][m] << '\n';
}