#region Header
#!/usr/bin/env python3
# from typing import *

import sys
import io
import math
import collections
import decimal
import itertools
from queue import PriorityQueue
import bisect
import heapq

def input():
    return sys.stdin.readline()[:-1]

sys.setrecursionlimit(1000000)
#endregion

# _INPUT = """5 8 11
# 2 2 231985796
# 6 0 190979457
# 7 2 373925694
# 8 2 976892608
# 8 1 184831039
# """
# sys.stdin = io.StringIO(_INPUT)



def main():
    N, V, L = map(int, input().split())
    x = [0] + [None for _ in range(N)] + [L]
    v = [0] + [None for _ in range(N)] + [0]
    w = [0] + [None for _ in range(N)] + [0]
    for i in range(N):
        x[i+1], v[i+1], w[i+1] = map(int, input().split())
        if x[i+1] - x[i] > V:
            print(-1)
            return
    if x[N+1] - x[N] > V:
            print(-1)
            return

    dp = [10**10 for _ in range(V+1)]
    dp[V] = 0
    for i in range(N+1):
        dp1 = [10**10 for _ in range(V+1)]
        d = x[i+1] - x[i]
        for v1 in range(V+1):
            if dp[v1] < 10**10:
                if v1-(x[i+1]-x[i]) >= 0:
                    dp1[v1-d] = min(dp1[v1-d], dp[v1])
                v_filled = min(v1+v[i], V)
                if v_filled - d >= 0:
                    dp1[v_filled-d] = min(dp1[v_filled-d], dp[v1] + w[i])
        dp = dp1

    MinW = min(dp)
    if MinW == 10**10:
        print(-1)
    else:
        print(MinW)

if __name__ == '__main__':
    main()