import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import numpy as np

N, V, L = map(int, readline().split())
m = map(int, read().split())

INF = 10 ** 15

dp = np.zeros(V + 1, np.int64)
now_x = 0
for x, v, w in zip(m, m, m):
    dx = x - now_x
    now_x = x
    if dx > V:
        print(-1)
        exit()
    newdp = np.full_like(dp, INF)
    # まず、使う
    dp = dp[dx:]
    # 買わない場合
    np.minimum(dp, newdp[: len(dp)], out=newdp[: len(dp)])
    # 買う場合
    if v > V:
        v = V
    n = min(V - v, len(dp) - 1)
    np.minimum(dp[: n + 1] + w, newdp[v: n + v + 1], out=newdp[v: n + v + 1])
    # あふれるほど買う
    if len(dp) > V - v:
        x = dp[V - v:].min() + w
        if newdp[-1] > x:
            newdp[-1] = x
    dp = newdp

dx = L - now_x
if dx > V:
    print(-1)
    exit()

dp = dp[dx:]
x = dp.min()
if x >= INF:
    x = -1
print(x)