import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N, V, L = getlist()
	DP = [[INF] * (V + 1) for i in range(N + 2)]
	DP[0][V] = 0
	xnow = 0
	for i in range(1, N + 1):
		x, v, w = getlist()
		for j in range(V + 1):
			if j + (x - xnow) <= V:
				DP[i][j] = min(DP[i][j], DP[i - 1][j + (x - xnow)])
			DP[i][min(V, j + v)] = min(DP[i][min(V, j + v)], DP[i][j] + w)
			# if j >= v:
			# 	DP[i][j] = min(DP[i][j], DP[i][j - v] + w)
		xnow = x

	for j in range(V + 1):
		if j + (L - xnow) <= V:
			DP[N + 1][j] = min(DP[N + 1][j], DP[N][j + (L - xnow)])

	# print(DP)

	ans = min(DP[-1])
	if ans == INF:
		print(-1)
	else:
		print(ans)

if __name__ == '__main__':
	main()