CF1827A.Counting Orders

传统题 时间 2000 ms 内存 256 MiB 5 尝试 1 已通过 1 标签

Counting Orders

You are given two arrays aa and bb each consisting of nn integers. All elements of aa are pairwise distinct.

Find the number of ways to reorder aa such that ai>bia_i \gt b_i for all 1in1 \le i \le n, modulo 109+710^9 + 7.

Two ways of reordering are considered different if the resulting arrays are different.

Input

Each test contains multiple test cases. The first line contains the number of test cases tt (1t1041 \le t \le 10^4). The description of the test cases follows.

The first line of each test case contains a single integer nn (1n21051 \le n \le 2 \cdot 10^{5}) — the length of the array aa and bb.

The second line of each test case contains nn distinct integers a1a_1, a2a_2, \ldots, ana_n (1ai1091 \le a_i \le 10^9) — the array aa. It is guaranteed that all elements of aa are pairwise distinct.

The second line of each test case contains nn integers b1b_1, b2b_2, \ldots, bnb_n (1bi1091 \le b_i \le 10^9) — the array bb.

It is guaranteed that the sum of nn over all test cases does not exceed 21052 \cdot 10^{5}.

Output

For each test case, output the number of ways to reorder array aa such that ai>bia_i \gt b_i for all 1in1 \le i \le n, modulo 109+710^9 + 7.

Samples

5
6
9 6 8 4 5 2
4 1 5 6 3 1
3
4 3 2
3 4 9
1
2
1
3
2 3 4
1 3 3
12
2 3 7 10 23 28 29 50 69 135 420 1000
1 1 2 3 5 8 13 21 34 55 89 144
32
0
1
0
13824

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