N people stand in a line, and we numbered them 1,2...n, and now you are asked to rearrange them. The ith people is considred in the front of the (i+1)th, after the rearrange, everyone the people in front of whom can not be the same one as before. How many different strategies you can do the rearrange.
Input:
Each test case just contains one integer, the number of people you have to rearrange.
Output:
The number of strategies you have to rearrange them, with the condition above.
Sample Input:
3
4
Sample Output:
3
11
