func main()
	var n: int :: cui@inputInt()
	var ans: int :: c(n)
	do cui@print("\{ans}\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