> # include <stdio.h>
> # include <stdbool.h>
> bool data[21][21][21];
> bool used[21][21][21];
> bool face1[9][21][21],face2[9][21][21],face3[9][21][21];
> int n;
> void test()
> {
>   int i,j,k;
>   printf("face1\n");
>   for(k=1;k<=8;k++)
>   {
>    printf("num=%d\n",k);
>    for(i=1;i<=n;i++)
>    {
>     for(j=1;j<=n;j++) 
>       if(face1[k][i][j]) printf("●");
>       else printf("  "); 
>     printf("\n");
>    }
>    printf("\n");
>   }
>   printf("face2\n");
>   for(k=1;k<=8;k++)
>   {
>    printf("num=%d\n",k);
>    for(i=1;i<=n;i++)
>    {
>     for(j=1;j<=n;j++) 
>       if(face2[k][i][j]) printf("●");
>       else printf("  "); 
>     printf("\n");
>    }
>    printf("\n");
>   }
>   printf("face3\n");
>   for(k=1;k<=8;k++)
>   {
>    printf("num=%d\n",k);
>    for(i=1;i<=n;i++)
>    {
>     for(j=1;j<=n;j++) 
>       if(face3[k][i][j]) printf("●");
>       else printf("  "); 
>     printf("\n");
>    }
>    printf("\n");
>   }
> }
> void dfs(int x,int y,int z)
> {
>      if(x<1||x>n||y<1||y>n||z<1||z>n) return;
>      else if(used[x][y][z]) return;
>      else if(!data[x][y][z]) return;
>      else
>      {
>        used[x][y][z]=1;
>        dfs(x+1,y,z);
>        dfs(x-1,y,z);
>        dfs(x,y+1,z);
>        dfs(x,y-1,z);
>        dfs(x,y,z+1);
>        dfs(x,y,z-1);
>      }
> }
> void makeface()
> {
>    int i,j,k;
>    for(k=2;k<=4;k++)
>      for(i=1;i<=n;i++)
>       for(j=1;j<=n;j++)
>       {
>        face1[k][j][n-i+1]=face1[k-1][i][j];
>        face2[k][j][n-i+1]=face2[k-1][i][j];
>        face3[k][j][n-i+1]=face3[k-1][i][j];
>       }
>    for(k=1;k<=4;k++)
>       for(i=1;i<=n;i++)
>         for(j=1;j<=n;j++)
>         {
>           face1[k+4][n-i+1][j]=face1[k][i][j];
>           face2[k+4][n-i+1][j]=face2[k][i][j];
>           face3[k+4][n-i+1][j]=face3[k][i][j];
>         }
> }
> void makeblock(int c1,int c2,int c3)
> {
>      int i,j,k;
>      for(i=1;i<=n;i++)
>       for(j=1;j<=n;j++)
>         if(!face1[c1][i][j])
>           for(k=1;k<=n;k++)
>             data[i][j][k]=0;  
>      for(i=1;i<=n;i++)
>       for(j=1;j<=n;j++)
>         if(!face2[c2][i][j])
>           for(k=1;k<=n;k++)
>             data[k][i][j]=0;
>      for(i=1;i<=n;i++)
>       for(j=1;j<=n;j++)
>         if(!face3[c3][i][j])
>           for(k=1;k<=n;k++)
>             data[i][k][j]=0;            
> }
> bool chkthrouth(int c1,int c2,int c3)
> {
>      int i,j,k;
>      for(i=1;i<=n;i++)
>       for(j=1;j<=n;j++)
>         if(face1[c1][i][j])
>         {
>           bool flag=0;
>           for(k=1;k<=n;k++)
>             if(data[i][j][k]) {flag=1;break;}
>           if(!flag) return 0;
>         }  
>      for(i=1;i<=n;i++)
>       for(j=1;j<=n;j++)
>         if(face2[c2][i][j])
>         {
>          bool flag=0;
>           for(k=1;k<=n;k++)
>             if(data[k][i][j]) {flag=1;break;}
>           if(!flag) return 0;
>          }
>      for(i=1;i<=n;i++)
>       for(j=1;j<=n;j++)
>         if(face3[c3][i][j])
>         {
>           bool flag=0;
>           for(k=1;k<=n;k++)
>             if(data[i][k][j]) {flag=1;break;}
>           if(!flag) return 0;
>         }  
>         return 1;          
> }
> bool sub_jud()
> {
>      int x,y,z;
>      memset(used,0,sizeof(used));
>      for(x=1;x<=n;x++)
>        for(y=1;y<=n;y++)
>        {
>           if(!used[x][y][1]&&data[x][y][1])
>              {dfs(x,y,1);goto here;}
>        }  
>      here:;
>      for(x=1;x<=n;x++) 
>        for(y=1;y<=n;y++)
>          for(z=1;z<=n;z++)
>            if(!used[x][y][z]&&data[x][y][z]) return 0;
>      return 1;
> }
> bool jud()
> {
>     makeface(); 
> 
>     int i,j,k;
>     for(i=1;i<=8;i++)
>       for(j=1;j<=8;j++)
>         for(k=1;k<=8;k++)
>         {
>          memset(data,1,sizeof(data));
>          makeblock(i,j,k);
>          if(chkthrouth(i,j,k)&&sub_jud()) return 1;
>         }
>    return 0;
> }
> int main()
> {
>     int count=0;
>     while(1)
>     {
>         scanf("%d",&n);
>         if(!n) break;
>         int i,j;
>         for(i=1;i<=n;i++)
>         {
>          getchar();
>          for(j=1;j<=n;j++)
>          {
>           char temp;
>           scanf("%c",&temp);
>           if(temp=='X') face1[1][j][i]=1;
>           else face1[1][j][i]=0;
>          }
>         }
>         for(i=1;i<=n;i++)
>         {
>          getchar();
>          for(j=1;j<=n;j++)
>          {
>           char temp;
>           scanf("%c",&temp);
>           if(temp=='X') face2[1][j][i]=1;
>           else face2[1][j][i]=0;
>          }
>         }
>         for(i=1;i<=n;i++)
>         {
>          getchar();
>          for(j=1;j<=n;j++)
>          {
>           char temp;
>           scanf("%c",&temp);
>           if(temp=='X') face3[1][j][i]=1;
>           else face3[1][j][i]=0;
>          }
>         }
>         if(jud()) printf("Data set %d: Valid set of patterns\n",++count);
>         else printf("Data set %d: Impossible combination\n",++count);
>     }
>     return 0;
> }
>         
>          
>         
>