1
2
0

1
1

#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
	_int64 ls[30]={0,0,1};
	_int64 gq[30]={1,1,2};
	for(int i=3;i<26;i++)
	{
		ls[i]=(i-1)*(ls[i-1]+ls[i-2]);
		gq[i]=gq[i-1]*i;
	}
	int n;
	while(cin>>n,n)
	{
		_int64 sum=0;
		if(n==1||n==2||n==3)
		{
			cout<<1<<endl;
		    continue;
		}
		for(int k=n/2;k>1;k--)
		sum+=gq[n]/(gq[k]*gq[n-k])*(ls[k]);
		
	printf("%I64d\n",sum+1);
	
	}
	return 0;
}