题目描述
Read problems statements in Mandarin Chinese and Russian.
Little Elephant and his friends are going to a party. Each person has his own collection of T-Shirts. There are 100 different kind of T-Shirts. Each T-Shirt has a unique id between 1 and 100. No person has two T-Shirts of the same ID.
They want to know how many arrangements are there in which no two persons wear same T-Shirt. One arrangement is considered different from another arrangement if there is at least one person wearing a different kind of T-Shirt in another arrangement.
------ Input ------
First line of the input contains a single integer T denoting number of test cases. Then T test cases follow.
For each test case, first line contains an integer N, denoting the total number of persons. Each of the next N lines contains at least 1 and at most 100 space separated distinct integers, denoting the ID's of the T-Shirts i^{th} person has.
------ Output ------
For each test case, print in single line the required number of ways modulo 1000000007 = 10^{9}+7.
------ Constraints ------
$1 ≤ T ≤ 10$
$1 ≤ N ≤ 10$
------ Example ------
Input:
2
2
3 5
8 100
3
5 100 1
2
5 100
Output:
4
4
------ Explanation ------
For the first case, 4 possible ways are (3,8), (3,100), (5,8) and (5,100).For the second case, 4 possible ways are (5,2,100), (100,2,5), (1,2,100), and (1,2,5).
输入格式
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输出格式
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