4
7

1 0   0 0   0 1   1 1   1 0   0 0   0 1 
1 1   1 1   1 0   0 1   1 1   1 0   0 0 

1 1   1 1   * *   * *   * *   * *   0 0 
0 0   0 1   * *   * *   * *   * *   1 1 

0 0   0 1   * *   * *   * *   * *   1 1 
1 1   1 0   * *   * *   * *   * *   0 1 

1 1   1 0   0 1   1 0   0 0   0 0   0 1 
1 1   1 1   1 1   1 0   0 0   0 1   1 1