#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<stack>
#include<queue>
#include<cstring>
#include<deque>
#define itn int
#define xlm mylove
using namespace std;
int n; int sum=0;
int x[20]; 
inline void readln(){
	freopen("queen.in","r",stdin);
	freopen("queen.out","w",stdout);
	scanf("%d",&n);
}
inline bool judge(int k)   
{   
    int i;   
    for(i=1;i<k;i++)   
      if(abs(k-i)==abs(x[k]-x[i]) || x[k] == x[i])   
        return 0;   
    return 1;   
}   
inline void search(int t){
	if (t>n)
      sum++;   
    else  
      for(int i=1;i<=n;i++)   
      {   
          x[t] = i;
          if(judge(t)) 
            search(t+1);    
      }     
}
int Main(){
	readln();
	search(1);
	printf("%d",sum);
	return 0;
}
int main(){;}
int xlm=Main();