#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define inf 10e17
#define rep(i,n) for(long long i=0; i<n; i++)
#define repr(i,n,m) for(long long i=m; i<n; i++)
#define mod 1000000007
#define sorti(x) sort(x.begin(), x.end())
#define sortd(x) sort(x.begin(), x.end(), std::greater<long long>())
#define debug(x) std::cerr << (x) << std::endl;
#define roll(x) for (auto&& itr : x) { cerr << (itr) << " "; }

template <class T> inline void chmax(T &ans, T t) { if (t > ans) ans = t;}
template <class T> inline void chmin(T &ans, T t) { if (t < ans) ans = t;}

int main() {
  ll N,V,L;
  cin >> N >> V >> L;
  vector<ll> x(N+1), v(N+1), w(N+1);
  x[0] = 0, v[0] = V, w[0] = 0;
  for (int i = 0; i < N; ++i) {
    cin >> x[i+1] >> v[i+1] >> w[i+1];
  }
  x.push_back(L);
  v.push_back(inf);
  w.push_back(inf);
  // dp(i,j) = 地点、残り燃料、最小のコスト
  vector<vector<ll>> dp(N+10, vector<ll>(V+10, inf));
  dp[0][V] = 0;
  for (int i = 1; i <= N+1; ++i) {
    ll dist = x[i] - x[i-1];
    for (int j = 0; j <= V; ++j) {
      if (dist + j <= V) {
        dp[i][j] = min(dp[i][j], dp[i-1][dist+j]);
        dp[i][min(j + v[i], V)] = min(dp[i][min(j + v[i], V)], dp[i][j] + w[i]);
      }
    }
  }

  ll ans = inf;
  for (auto itr : dp[N+1]) {
    chmin(ans, itr);
  }

  cout << ((ans == inf) ? -1 : ans) << endl;
}