#include <bits/stdc++.h>
#define REP(i, m, n) for(int i = (int)(m); i < (int)(n); ++i)
#define rep(i, n) REP(i, 0, n)
using namespace std;
using ll = long long;
using ld = long double;
template<class T, class U> inline bool chmax(T &a, const U &b) { if(a < b) { a = b; return true; } return false; }
template<class T, class U> inline bool chmin(T &a, const U &b) { if(a > b) { a = b; return true; } return false; }

int N, V, L, x[2010], v[2010], w[2010];
ll dp[2010][2010];

int main() {
  cin.tie(0); ios::sync_with_stdio(false);
  cin >> N >> V >> L;
  REP(i, 1, N+1) cin >> x[i] >> v[i] >> w[i];
  x[0] = w[0] = 0;
  v[0] = V;
  x[N+1] = L;
  rep(i, 2010) rep(j, 2010) dp[i][j] = (1LL<<60);
  dp[0][0] = 0;
  rep(i, N+1) rep(j, V+1) {
    if(min(V, j+v[i])-(x[i+1]-x[i]) >= 0) chmin(dp[i+1][min(V, j+v[i])-(x[i+1]-x[i])], dp[i][j]+w[i]);
    if(j-(x[i+1]-x[i]) >= 0) chmin(dp[i+1][j-(x[i+1]-x[i])], dp[i][j]);
  }
  ll ans = (1LL<<60);
  rep(j, V+1) {
    chmin(ans, dp[N+1][j]);
  }
  if(ans == (1LL<<60)) ans = -1;
  cout << ans << '\n';
  return 0;
}