#include<iostream>
#include<cstdio>
using namespace std;
int ai[10100]={0},n,maxn=0,ni[10100]={0};
long ans;
int work(int y);
int main()
{
	freopen("mushroom.in","r",stdin);
	freopen("mushroom.out","w",stdout);
	cin>>n;
	ai[1]=1;
	maxn=1;
	for(int i=0;i<n-1;i++)
	{
		work(i);
	}
	for(int i=0;i<=maxn;i++)
	{
		ans+=ai[i];
	}
	cout<<ans;
}
int work(int x)
{
	for(int i=0;i<=maxn;i++)
	{
		if(i!=0)
		{
		    ni[i-1]+=ai[i];
		}
	    ni[i+1]+=ai[i];
		ai[i]=0;
	}
	maxn++;
	for(int i=0;i<=maxn;i++)
	{
		ai[i]=ni[i];
		ni[i]=0;
	}
}