import sys
readline = sys.stdin.readline
N, V, L = map(int, readline().split())

xvw = [tuple(map(int, readline().split())) for _ in range(N)]
INF = 1<<60
dp = [INF]*(V+1)
dp[V] = 0

pre = 0
for x, v, w in xvw:
    dist = x-pre
    dp = dp[dist:] + [INF]*dist
    dp2 = dp[:]
    for vi in range(V+1):
        dp2[min(V, vi+v)] = min(dp2[min(V, vi+v)], dp[vi]+w)
    dp = dp2[:]
    pre = x
ans = min(dp[L-pre:])
if ans == INF:
    ans = -1
print(ans)