n guests each own an assigned seat numbered 1 to n. They reshuffle so that every guest ends up in some seat, but no guest sits in their own assigned seat. Count the number of such reshuffles (permutations with no fixed point).
Report the count modulo 1000000007. For n = 0 there is exactly one arrangement (the empty one).
Input format
A single line containing the integer n.
Output format
A single integer: the number of fixed-point-free permutations modulo 1000000007.
Constraints
- 0 <= n <= 1000