- Time limit: 1.00 s
- Memory limit: 512 MB
There are n children at a Christmas party, and each of them has brought a gift. The idea is that everybody will get a gift brought by someone else.
In how many ways can the gifts be distributed?
The only input line has an integer n: the number of children.
Print the number of ways modulo 10^9+7.
- 1 \le n \le 10^6