import java.util.Scanner;
import java.math.BigInteger;
import java.math.BigDecimal;
public class Main {
public static void main(String[] args)
{
int n=0;
BigInteger[] ans = new BigInteger[101];
Scanner input = new Scanner(System.in);
ans[0] = BigInteger.valueOf(1);
ans[1] = BigInteger.valueOf(1);
ans[2] = BigInteger.valueOf(2);
for(int i=3; i<101; i++)
{
ans[i] = BigInteger.valueOf(0);
for(int j=0; j<i; j++ )
{
ans[i] = ans[i].add(ans[j].multiply(ans[i-j-1]));
}
}
while(input.hasNextInt())
{
n = input.nextInt();
if(n == -1)
break;
System.out.println(ans[n]);
}
}
}