×

- 33.73%
- 1000ms
- 262144K

Morgana is learning computer vision, and he likes cats, too. One day he wants to find the cat movement from a cat video. To do this, he extracts cat features in each frame. A cat feature is a two-dimension vector <$x$, $y$>. If $x_i$ = $x_j$ and $y_i$ = $y_j$, then <$x_i$, $y_i$> <$x_j$, $y_j$> are same features.

So if cat features are moving, we can think the cat is moving. If feature <$a$, $b$> is appeared in continuous frames, it will form features movement. For example, feature <$a$ , $b$ > is appeared in frame $2,3,4,7,8$, then it forms two features movement $2-3-4$ and $7-8$ .

Now given the features in each frames, the number of features may be different, Morgana wants to find the longest features movement.

First line contains one integer $T(1 \le T \le 10)$ , giving the test cases.

Then the first line of each cases contains one integer $n$ (number of frames),

In The next $n$ lines, each line contains one integer $k_i$ ( the number of features) and $2k_i$ intergers describe $k_i$ features in ith frame.(The first two integers describe the first feature, the $3$rd and $4$th integer describe the second feature, and so on).

In each test case the sum number of features $N$ will satisfy $N \le 100000$ .

For each cases, output one line with one integers represents the longest length of features movement.

1 8 2 1 1 2 2 2 1 1 1 4 2 1 1 2 2 2 2 2 1 4 0 0 1 1 1 1 1 1

3