CRB and Puzzle

CRB is now playing Jigsaw Puzzle.
There are $N$ kinds of pieces with infinite supply.
He can assemble one piece to the right side of the previously assembled one.
For each kind of pieces, only restricted kinds can be assembled with.
How many different patterns he can assemble with at most $M$ pieces? (Two patterns $P$ and $Q$ are considered different if their lengths are different or there exists an integer $j$ such that $j$-th piece of $P$ is different from corresponding piece of $Q$.)

There are multiple test cases. The first line of input contains an integer $T$, indicating the number of test cases. For each test case:
The first line contains two integers $N$, $M$ denoting the number of kinds of pieces and the maximum number of moves.
Then $N$ lines follow. $i$-th line is described as following format.
k $a_{1}\ a_{2}\ ...\ a_{k}$
Here $k$ is the number of kinds which can be assembled to the right of the $i$-th kind. Next $k$ integers represent each of them.
1 ≤ $T$ ≤ 20
1 ≤ $N$ ≤ 50
1 ≤ $M$ ≤ $10^5$
0 ≤ $k$ ≤ $N$
1 ≤ $a_{1}$ < $a_{2}$ < … < $a_{k}$ ≤ N

For each test case, output a single integer - number of different patterns modulo 2015.

1
3 2
1 2
1 3
0

6

possible patterns are &#8709;, 1, 2, 3, 1→2, 2→3

KUT（DPRK）

2015 Multi-University Training Contest 10