import sys
sys.setrecursionlimit(10**6)

N, V, L = list(map(int, input().split()))
shop_list = [list(map(int, input().split())) for i in range(N)]

dp_dict = {}


def solve(i, j):
    if j < 0:
        return -1

    if (i, j) in dp_dict:
        return dp_dict[(i, j)]

    if i == N - 1:
        dis = L - shop_list[i][0]
        if j >= dis:
            dp_dict[(i, j)] = 0
            return 0
        elif j + shop_list[i][1] if j + shop_list[i][1] < V else V >= dis:
            dp_dict[(i, j)] = shop_list[i][2]
            return shop_list[i][2]
        else:
            dp_dict[(i, j)] = -1
            return -1

    dis = shop_list[i + 1][0] - shop_list[i][0]
    a = solve(i + 1, j - dis)
    j += shop_list[i][1]
    if j > V:
        j = V
    b = solve(i + 1, j - dis) + shop_list[i][2]

    if a == -1 and b == -1:
        dp_dict[(i, j)] = -1
        return -1
    else:
        if a == -1:
            dp_dict[(i, j)] = b
            return b
        elif b == -1:
            dp_dict[(i, j)] = a
            return a
        else:
            res = min([a, b])
            dp_dict[(i, j)] = res
            return res


if V - shop_list[0][0] < 0:
    print(-1)
else:
    print(solve(0, V - shop_list[0][0]))