#include <iostream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <cassert>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <bitset>
#include <string>
#include <algorithm>
#include <utility>
#define llint long long
#define inf 1e18
#define rep(x, s, t) for(llint (x) = (s); (x) < (t); (x)++)
#define Rep(x, s, t) for(llint (x) = (s); (x) <= (t); (x)++)
#define chmin(x, y) (x) = min((x), (y))
#define chmax(x, y) (x) = max((x), (y))
#define mod 1000000007

using namespace std;
typedef pair<llint, llint> P;

llint n, V, L;
llint x[2005], v[2005], w[2005];
llint dp[2005][2005];

int main(void)
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> V >> L;
	for(int i = 1; i <= n; i++) cin >> x[i] >> v[i] >> w[i];
	
	for(int i = 0; i <= n; i++){
		for(int j = 0; j <= V; j++){
			dp[i][j] = inf;
		}
	}
	dp[0][V] = 0;
	
	for(int i = 0; i < n; i++){
		llint d = x[i+1]-x[i];
		for(int j = d; j <= V; j++){
			chmin(dp[i+1][j-d], dp[i][j]);
			chmin(dp[i+1][min(V,j-d+v[i+1])], dp[i][j]+w[i+1]);
		}
	}
	
	llint ans = inf, d = L-x[n];
	for(int j = d; j <= V; j++) ans = min(ans, dp[n][j]);
	if(ans > inf/2) ans = -1;
	cout << ans << endl;
	
	return 0;
}