mod = 1000000007
eps = 10 ** -9
inf = 10 ** 15


def main():
    import sys
    input = sys.stdin.buffer.readline

    N, Vmax, L = map(int, input().split())
    X = [0] * (N + 1)
    V = [0] * (N + 1)
    W = [0] * (N + 1)
    for i in range(1, N + 1):
        x, v, w = map(int, input().split())
        X[i] = x
        V[i] = v
        W[i] = w
    X.append(L)
    V.append(0)
    W.append(0)

    dp = [[inf] * (Vmax + 1) for _ in range(N + 2)]
    dp[0][Vmax] = 0
    for i in range(1, N + 2):
        x, v, w = X[i], V[i], W[i]
        d = x - X[i-1]
        for j in range(Vmax+1):
            if j - d >= 0:
                dp[i][j-d] = min(dp[i][j-d], dp[i-1][j])
                dp[i][min(Vmax, j-d + v)] = min(dp[i][min(Vmax, j-d+v)], dp[i-1][j] + w)
    ans = min(dp[-1])
    if ans == inf:
        print(-1)
    else:
        print(ans)


if __name__ == '__main__':
    main()