#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
int main ()
{
	int n,ans=1;
	cin>>n;
	int arr[1010];
	memset(arr,1,sizeof(arr)); 
	for(int i=1;i<=n/2;i++)
	{
		for(int j=1;j<=i/2;j++)
		{
			arr[i]+=arr[j];	
		}
		ans+=arr[i]; 
	}
	cout<<ans;
	return 0;
}