N, V, L = map(int, input().split())
x = [[0, 0] for i in range(L + 1)] # 容量 かかる費用
for i in range(N):
    t, m, p = map(int, input().split())
    x[t] = [m, p]

dp = [[float('inf') for i in range(V + 1)] for j in range(L + 1)]
dp[0][V] = 0

for i in range(L):
    for j in range(V + 1):
        if dp[i][j] != float('inf'):
            dp[i][min(x[i][0] + j, V)] = min(dp[i][j] + x[i][1], dp[i][min(x[i][0] + j, V)])
            if j > 0:
                dp[i + 1][j - 1] = min(dp[i + 1][j - 1], dp[i][j])

ans = float('inf')
for i in dp[L]:
    ans = min(ans, i)

print(ans if ans != float('inf') else -1)