#include<iostream>
#include<cstdio>
using namespace std;
bool lie[100],yz[100],zy[100];
int num,n;
int search(int i)
{
    for(int j=1;j<=n;j++)
	{
        if(!lie[j]&&!yz[i+j]&&!zy[i-j+n])
		{
 			lie[j]=1;
			yz[i+j]=1;
			zy[i-j+n]=1;
			if(i==n)
			  num++;
   			else 
			  search(i+1);
			lie[j]=0;
			yz[i+j]=0;
			zy[i-j+n]=0;
		}
	}
}
int main()
{
	freopen ("queen.in","r",stdin);
	freopen ("queen.out","w",stdout);
	cin>>n;
	search(1);
	cout<<num;
	return 0;
}