#include <cassert>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <map>
#include <queue>
#include <set>
#include <cstring>
#include <vector>

using namespace std;
typedef long long ll;

int main() {
  ll N, VL, L;
  cin >> N >> VL >> L;

  vector<ll> X(N + 2);
  vector<ll> V(N + 2);
  vector<ll> W(N + 2);
  X[0] = 0;
  V[0] = 0;
  W[0] = 0;

  for (int i = 1; i <= N; ++i) {
    cin >> X[i] >> V[i] >> W[i];
  }
  X[N + 1] = L;
  V[N + 1] = 0;
  W[N + 1] = 0;

  vector<vector<ll>> dp(N + 2, vector<ll>(VL + 1, LLONG_MAX));
  dp[0][VL] = 0;

  for (int i = 0; i <= N; ++i) {
    int dist = X[i + 1] - X[i];

    for (int v = VL; v >= 0; --v) {
      if (dp[i][v] == LLONG_MAX) continue;

      int nv = v - dist;
      if (nv < 0) break;

      dp[i + 1][nv] = min(dp[i + 1][nv], dp[i][v]);
      ll cv = min(VL, nv + V[i + 1]);
      dp[i + 1][cv] = min(dp[i + 1][cv], dp[i + 1][nv] + W[i + 1]);
    }

    for (int v = VL - 1; v >= 0; --v) {
      dp[i + 1][v] = min(dp[i + 1][v], dp[i + 1][v + 1]);
    }
  }

  ll ans = LLONG_MAX;

  for (int v = 0; v <= VL; ++v) {
    ans = min(ans, dp[N + 1][v]);
  }

  if (ans == LLONG_MAX) {
    cout << -1 << endl;
  } else {
    cout << ans << endl;
  }


  return 0;
}