#include<iostream>

 #include<cstdio>

 int Queen[],n;

 int dp[];

 int dfs(int k)

 {

     if (k>n)

     return ;

     int ans = ;

     for (int i =  ;i<= n ;i++)

     {

     int nx = k, ny = i;//把第k个皇后放在第k行

     bool isOk = true;

     for (int j = ; j< k && isOk ;j++)

     {

     int prex = j, prey = Queen[j];//放过的皇后

     if (prey == ny || prey-prex == ny-nx || prey + prex == ny + nx)//在同一列、一个对角线 不合法

     isOk = false;

         }

          if (isOk)

         {

          Queen[k] = i;//k个皇后在k行i列

          ans += dfs(k+);

         }

     }

     return ans;

 }

 int main()

  {

     while(scanf ("%d",&n)&&n!=)

     {

         //缩短时间

         if (dp[n]==)

         dp[n]=dfs();

         printf ("%d\n",dp[n]);

         }

     return ;

 }