Problem A

Expression Bracketing

Input: standard input

Output: standard output

Time Limit: 1 second

Memory Limit: 32 MB

In this problem you will have to find in how many ways n letters can be bracketed so that the bracketing is non-binary bracketing. For example 4 letters have 11 possible bracketing:

xxxx, (xx)xx, x(xx)x, xx(xx), (xxx)x, x(xxx), ((xx)x)x, (x(xx))x, (xx)(xx), x((xx)x), x(x(xx)). Of these the first six bracketing are not binary. Given the number of letters you will have to find the total number of non-binary bracketing.

Input

The input file contains several lines of input. Each line contains a single integer n (0<n<=26). Input is terminated by end of file.

Output

For each line of input produce one line of output which denotes the number of non binary bracketing with n letters.

Sample Input

3

4

5

10

Sample Output

1

6

31

98187

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(The Decider Contest, Problem setter: Shahriar Manzoor)