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 dp[] = new BigInteger [110] ;
		dp[0]=BigInteger.valueOf(1);
		dp[1]=BigInteger.valueOf(1);
		dp[2]=BigInteger.valueOf(2);
		for ( int i = 3 ; i <= 100 ; i ++ ) {
			dp[i]=BigInteger.valueOf(0);
			for ( int j = 0 ; j < i ; j ++ ) {
				dp[i]=dp[i].add(dp[j].multiply(dp[i-j-1]));
			}
		}
		while ( cin . hasNext ( ) ) {
			int x ;
			x = cin . nextInt ( ) ;
			if ( x == -1 ) {
				break ;
			}
			System.out.println(dp[x]) ;
		}
	}
}