#abc214g. [abc214_g]Three Permutations

[abc214_g]Three Permutations

Problem Statement

Given are permutations of (1,dots,N)(1, \\dots, N): p=(p1,dots,pN)p = (p_1, \\dots, p_N) and q=(q1,dots,qN)q = (q_1, \\dots, q_N).

Find the number, modulo (109+7)(10^9 + 7), of permutations r=(r1,dots,rN)r = (r_1, \\dots, r_N) of (1,dots,N)(1, \\dots, N) such that rineqpir_i \\neq p_i and rineqqir_i \\neq q_i for every ii (1leqileqN)(1 \\leq i \\leq N).

Constraints

  • 1leqNleq30001 \\leq N \\leq 3000
  • 1leqpi,qileqN1 \\leq p_i, q_i \\leq N
  • pineqpj,(ineqj)p_i \\neq p_j \\, (i \\neq j)
  • qineqqj,(ineqj)q_i \\neq q_j \\, (i \\neq j)
  • All values in input are integers.

Input

Input is given from Standard Input in the following format:

NN p1p_1 ldots\\ldots pNp_N q1q_1 ldots\\ldots qNq_N

Output

Print the answer.


Sample Input 1

4
1 2 3 4
2 1 4 3

Sample Output 1

4

There are four valid permutations: (3,4,1,2)(3, 4, 1, 2), (3,4,2,1)(3, 4, 2, 1), (4,3,1,2)(4, 3, 1, 2), and (4,3,2,1)(4, 3, 2, 1).


Sample Input 2

3
1 2 3
2 1 3

Sample Output 2

0

The answer may be 00.


Sample Input 3

20
2 3 15 19 10 7 5 6 14 13 20 4 18 9 17 8 12 11 16 1
8 12 4 13 19 3 10 16 11 9 1 2 17 6 5 18 7 14 20 15

Sample Output 3

803776944

Be sure to print the count modulo (109+7)(10^9 + 7).