n, V_, l = map(int, input().split())
X = [-1] * n
V = [-1] * n
W = [-1] * n
for i in range(n):
    X[i], V[i], W[i] = map(int, input().split())
bef = 0
inf = 1 << 60
dp = [inf] * (V_ + 1)
dp[V_] = 0
for x, v, w in zip(X, V, W):
    d = x - bef
    bef = x
    ndp = [inf] * (V_ + 1)
    for i in range(d, V_ + 1):
        ndp[i - d] = dp[i]
    for i in range(V_, -1, -1):
        j = min(V_, i + v)
        ndp[j] = min(ndp[j], ndp[i] + w)
    dp = ndp
d = l - bef
try:
    ans = min(dp[d:])
    if ans == inf:
        ans = -1
    print(ans)
except:
    print(-1)