#include<stdio.h>
long long c[1000005];
int main()
{
	freopen("dirichlet.in","r",stdin);
	freopen("dirichlet.out","w",stdout);
	long n,i,nn_fact,rez,n_fact,comb,j;
	scanf("%ld",&n);
	c[0]=1;
	c[1]=1;
	for(i=2;i<=n;i++)
	{
		for(j=0;j<=i-1;j++)
			c[i]=c[i]+c[j]*c[i-j-1];
	}	
	printf("%ld\n",c[n]);
	return 0;
}