using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Globalization;

class Program
{
    static int NN => int.Parse(ReadLine());
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    static long[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, v, l) = (c[0], c[1], c[2]);
        var map = NArr(n);
        var INF = long.MaxValue / 2;
        var init = Enumerable.Repeat(INF, (int)v + 1).ToArray();
        var dp = new long[n + 2][];
        for (var i = 0; i < dp.Length; ++i) dp[i] = (long[])init.Clone();
        dp[0][v] = 0;
        if (map[0][0] <= v) dp[1][v - map[0][0]] = 0;
        for (var i = 0; i < n; ++i)
        {
            for (var j = 0; j <= v; ++j)
            {
                if (i + 1 == n)
                {
                    var len = l - map[i][0];
                    if (j >= len) dp[n + 1][j - len] = Math.Min(dp[n + 1][j - len], dp[i + 1][j]);
                    var max = Math.Min(v, j + map[i][1]);
                    if (max >= len) dp[n + 1][max - len] = Math.Min(dp[n + 1][max - len], dp[i + 1][j] + map[i][2]);
                }
                else
                {
                    var len = map[i + 1][0] - map[i][0];
                    if (j >= len) dp[i + 2][j - len] = Math.Min(dp[i + 2][j - len], dp[i + 1][j]);
                    var max = Math.Min(v, j + map[i][1]);
                    if (max >= len) dp[i + 2][max - len] = Math.Min(dp[i + 2][max - len], dp[i + 1][j] + map[i][2]);
                }
            }
        }
        var ans = INF;
        for (var i = 0; i <= v; ++i) ans = Math.Min(ans, dp[^1][i]);
        WriteLine(ans == INF ? -1 : ans);
    }
}