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
(The Decider Contest, Problem setter: Shahriar Manzoor)