import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int v = sc.nextInt();
        int l = sc.nextInt();
        GS[] stations = new GS[n + 2];
        for (int i = 1; i <= n; i++) {
            stations[i] = new GS(sc.nextInt(), sc.nextInt(), sc.nextInt());
        }
        stations[0] = new GS(0, 0, 0);
        stations[n + 1] = new GS(l, 0, 0);
        ArrayList<HashMap<Integer, Long>> dp = new ArrayList<>();
        for (int i = 0; i <= n + 1; i++) {
            dp.add(new HashMap<>());
        }
        dp.get(0).put(v, 0L);
        for (int i = 1; i <= n + 1; i++) {
            int length = stations[i].point - stations[i - 1].point;
            HashMap<Integer, Long> map = dp.get(i);
            for (Map.Entry<Integer, Long> entry : dp.get(i - 1).entrySet()) {
                int gas = entry.getKey() - length;
                if (gas < 0) {
                    continue;
                }
                if (map.containsKey(gas)) {
                    if (map.get(gas) > entry.getValue()) {
                        map.put(gas, entry.getValue());
                    }
                } else {
                    map.put(gas, entry.getValue());
                }
                long cost = entry.getValue() + stations[i].cost;
                gas = Math.min(v, gas + stations[i].gas);
                if (map.containsKey(gas)) {
                    if (map.get(gas) > cost) {
                        map.put(gas, cost);
                    }
                } else {
                    map.put(gas, cost);
                }
            }
        }
        if (dp.get(n + 1).size() == 0) {
            System.out.println(-1);
            return;
        }
        long min = Long.MAX_VALUE;
        for (long x : dp.get(n + 1).values()) {
            min = Math.min(x, min);
        }
        System.out.println(min);
    }
    
    static class GS {
        int point;
        int gas;
        int cost;
        
        public GS(int point, int gas, int cost) {
            this.point = point;
            this.gas = gas;
            this.cost = cost;
        }
    }
}