CF1882B.Sets and Union

You have $n$ sets of integers $S_{1}, S_{2}, \ldots, S_{n}$. We call a set $S$ attainable, if it is possible to choose some (possibly, none) of the sets $S_{1}, S_{2}, \ldots, S_{n}$ so that $S$ is equal to their union$^{\dagger}$. If you choose none of $S_{1}, S_{2}, \ldots, S_{n}$, their union is an empty set.

Find the maximum number of elements in an attainable $S$ such that $S \neq S_{1} \cup S_{2} \cup \ldots \cup S_{n}$.

$^{\dagger}$ The union of sets $A_1, A_2, \ldots, A_k$ is defined as the set of elements present in at least one of these sets. It is denoted by $A_1 \cup A_2 \cup \ldots \cup A_k$. For example, ${2, 4, 6} \cup {2, 3} \cup {3, 6, 7} = {2, 3, 4, 6, 7}$.

你有 $n$ 个整数集合 $S_{1}, S_{2}, \ldots, S_{n}$。我们称一个集合 $S$ 是可达成的（attainable），如果能够从 $S_{1}, S_{2}, \ldots, S_{n}$ 中选出若干个（可能一个也不选），使得 $S$ 恰好等于这些被选出集合的并集$^{\dagger}$。若一个集合都不选，则它们的并集为空集。

求所有满足 $S \neq S_{1} \cup S_{2} \cup \ldots \cup S_{n}$ 的可达成集合 $S$ 中，元素个数的最大值。

$^{\dagger}$ 集合 $A_1, A_2, \ldots, A_k$ 的并集定义为至少属于其中某一个集合的所有元素构成的集合，记作 $A_1 \cup A_2 \cup \ldots \cup A_k$。例如，${2, 4, 6} \cup {2, 3} \cup {3, 6, 7} = {2, 3, 4, 6, 7}$。

Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 100$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 50$).

The following $n$ lines describe the sets $S_1, S_2, \ldots, S_n$. The $i$-th of these lines contains an integer $k_{i}$ ($1 \le k_{i} \le 50$) — the number of elements in $S_{i}$, followed by $k_{i}$ integers $s_{i, 1}, s_{i, 2}, \ldots, s_{i, k_{i}}$ ($1 \le s_{i, 1} \lt s_{i, 2} \lt \ldots \lt s_{i, k_{i}} \le 50$) — the elements of $S_{i}$.

每个测试包含多个测试用例。第一行包含测试用例的数量 $t$（$1 \le t \le 100$）。随后是各测试用例的描述。

每个测试用例的第一行包含一个整数 $n$（$1 \le n \le 50$）。

接下来的 $n$ 行描述集合 $S_1, S_2, \ldots, S_n$。其中第 $i$ 行包含一个整数 $k_{i}$（$1 \le k_{i} \le 50$）——表示集合 $S_{i}$ 中元素的个数，随后是 $k_{i}$ 个整数 $s_{i, 1}, s_{i, 2}, \ldots, s_{i, k_{i}}$（$1 \le s_{i, 1} \lt s_{i, 2} \lt \ldots \lt s_{i, k_{i}} \le 50$）——即集合 $S_{i}$ 的所有元素。

For each test case, print a single integer — the maximum number of elements in an attainable $S$ such that $S \neq S_{1} \cup S_{2} \cup \ldots \cup S_{n}$.

对于每个测试用例，输出一个整数——即可达到的集合 $S$ 的最大元素个数，满足 $S \neq S_{1} \cup S_{2} \cup \ldots \cup S_{n}$。

In the first test case, $S = S_{1} \cup S_{3} = {1, 2, 3, 4}$ is the largest attainable set not equal to $S_1 \cup S_2 \cup S_3 = {1, 2, 3, 4, 5}$.

In the second test case, we can pick $S = S_{2} \cup S_{3} \cup S_{4} = {2, 3, 4, 5, 6}$.

In the third test case, we can pick $S = S_{2} \cup S_{5} = S_{2} \cup S_{3} \cup S_{5} = {3, 5, 6, 8, 9, 10}$.

In the fourth test case, the only attainable set is $S = \varnothing$.

在第一个测试用例中，$S = S_{1} \cup S_{3} = {1, 2, 3, 4}$ 是可达到的最大集合，且不等于 $S_1 \cup S_2 \cup S_3 = {1, 2, 3, 4, 5}$。

在第二个测试用例中，我们可以选取 $S = S_{2} \cup S_{3} \cup S_{4} = {2, 3, 4, 5, 6}$。

在第三个测试用例中，我们可以选取 $S = S_{2} \cup S_{5} = S_{2} \cup S_{3} \cup S_{5} = {3, 5, 6, 8, 9, 10}$。

在第四个测试用例中，唯一可达到的集合是 $S = \varnothing$。