链接：HDU 1023

/****************************************

 *       author        :  Grant Yuan

 *       time            :   2014/10/19 15:51

 *       source       :    HDU 1023

 *       algorithm :     Catalan数+高精度

 * ***************************************/

import java.io.*;

import java.math.*;

import java.util.*;

public class Main{

	public static void main(String args[])

	{

		Scanner cin=new Scanner(System.in);

		BigInteger []a = new BigInteger [105];

		BigInteger t;

		a[0]=a[1]=BigInteger.ONE;

		for(int  i=2;i<=102;i++)

		{

			a[i]=a[i-1].multiply(BigInteger.valueOf(4*i-2)).divide(BigInteger.valueOf(i+1));

		}

		while(cin.hasNext()){

			int n=cin.nextInt();

			if(n==-1) break;

			String str;

			str=a[n].toString();

			System.out.println(str);

		}

	}

}