Combinatorial structures

Plus

Problem description Progress

Output N-th number of Catalan

Input

The first line of the input contains a single number N (\(1 <= N <= 20\)).

Output

Print one number - Nth number of Catalan

#	Input	Output
1	1	1

Print the difference between the number of binary trees with N leaves and the number of partitions of the N-gon into triangles.

Input

The input is a single number - N (\(1 <= N <= 10\))

Output

Print one number - the desired difference

#	Input	Output
1	1	0