func main()
	var N: int :: cui@input().toInt(&)
	do cui@print("\{C(N)}\n")

	func C(n: int): int
		if (n < 2)
			ret 1
		end if
		var res: int
		for i(0, n - 1)
			do res :+ C(i) * C(n - 1 - i)
		end for
		ret res
	end func
end func