import sys
input = sys.stdin.readline
inf = 10 ** 18

N, V, L = map(int, input().split())
station = [tuple(map(int, input().split())) for _ in range(N)]
station.append((L, 0, 0))

dp = [inf] * (V + 1)
dp[V] = 0

pos = 0
for x, v, w in station:
    dist = x - pos
    newDP = [inf] * (V + 1)
    for i in range(dist, V + 1):
        # 補給しない
        gas = i - dist
        newDP[gas] = min(newDP[gas], dp[i])
        # 補給する
        gas = min(V, i - dist + v)
        newDP[gas] = min(newDP[gas], dp[i] + w)
    dp = newDP
    pos = x

ans = min(dp)
if ans >= inf:
    print(-1)
else:
    print(ans)