/* -*- coding: utf-8 -*-
 *
 * 1037.cc:  No.1037 exhausted - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 2000;
const int MAX_V = 2000;
const long long LINF = 1LL << 62;

/* typedef */

typedef long long ll;

/* global variables */

int xs[MAX_N + 2], vs[MAX_N + 1], wis[MAX_N + 1];
ll dp[MAX_N + 2][MAX_V + 1];

/* subroutines */

inline void setmin(ll &a, ll b) { if (a > b) a = b; }

/* main */

int main() {
  int n, v, l;
  scanf("%d%d%d", &n, &v, &l);

  for (int i = 1; i <= n; i++)
    scanf("%d%d%d", xs + i, vs + i, wis + i);
  xs[0] = vs[0] = wis[0] = 0;
  xs[n + 1] = l;

  for (int i = 0; i <= n + 1; i++) fill(dp[i], dp[i] + v + 1, LINF);

  dp[0][v] = 0;
  for (int i = 0; i <= n; i++)
    for (int j = 0; j <= v; j++)
      if (dp[i][j] < LINF) {
	int l = xs[i + 1] - xs[i];

	if (j >= l) setmin(dp[i + 1][j - l], dp[i][j]);

	if (vs[i] > 0) {
	  int j1 = min(v, j + vs[i]);
	  if (j1 >= l) setmin(dp[i + 1][j1 - l], dp[i][j] + wis[i]);
	}
      }

  ll mind = LINF;
  for (int j = 0; j <= v; j++) setmin(mind, dp[n + 1][j]);

  printf("%lld\n", (mind >= LINF) ? -1LL : mind);
  return 0;
}