The first line of input contains an integer t (1 ≤ t ≤ 10\, 000), which is the number of test cases. The descriptions of t test cases follow.

The first line of each test case contains two integers n and m, where n (1 ≤ n ≤ 2 \cdot 10^5) is the number of cats, and m (1 ≤ m ≤ 2 \cdot 10^5) is the number of catnip plants (and also the number of pots). Catnip plants are numbered from 1 to m.

The following n lines each describe one cat. The line starts with two integers p and k, where p (1 ≤ p ≤ m) is the pot at which the cat should stop, and k (1 ≤ k ≤ m) is the number of catnip plants the cat likes. The remainder of the line contains k distinct integers, which are the numbers of the plants that the cat likes.

Over all test cases, the sum of n is at most 2 \cdot 10^5, the sum of m is at most 2 \cdot 10^5, and the sum of all k is at most 5 \cdot 10^5.

#10897 upload 2 done 1 how_to_reg 1

고양이 몰기 timer 2s memory 2048MB

#10897

고양이 몰기 2s 2048MB