Score : 700 points
Snuke has a permutation (P_0,P_1,\cdots,P_{N-1}) of (0,1,\cdots,N-1).
Now, he will perform the following operation exactly once:
Find the number of permutations that can be produced as P after the operation.
Input is given from Standard Input in the following format:
N K P_0 P_1 \cdots P_{N-1}
Print the number of permutations that can be produced as P after the operation.
5 3 0 2 1 4 3
2
Two permutations can be produced as P after the operation: (0,1,2,4,3) and (0,2,1,3,4).
4 4 0 1 2 3
1
10 4 2 0 1 3 7 5 4 6 8 9
6