Problem Statement
There are ~N~ computers and ~N~ sockets in a one-dimensional world. The coordinate of the ~i~ -th computer is ~a_i~ , and the coordinate of the ~i~ -th socket is ~b_i~ . It is guaranteed that these ~2N~ coordinates are pairwise distinct.
Snuke wants to connect each computer to a socket using a cable. Each socket can be connected to only one computer.
In how many ways can he minimize the total length of the cables? Compute the answer modulo ~10^9+7~ .
Constraints
- ~1 ≤ N ≤ 10^5~
- ~0 ≤ a_i, b_i ≤ 10^9~
- The coordinates are integers.
- The coordinates are pairwise distinct.
Input
The input is given from Standard Input in the following format:
~N~
~a_1~
~a_N~
~b_1~
~b_N~
Output
Print the number of ways to minimize the total length of the cables, modulo ~10^9+7~ .
Sample Input 1
2
0
10
20
30
Sample Output 1
2
There are two optimal connections: ~0-20, 10-30~ and ~0-30, 10-20~ . In both connections the total length of the cables is ~40~ .
Sample Input 2
3
3
10
8
7
12
5
Sample Output 2
1
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