code table:
 ****
*****
* ***
  ***
  ** 
 *** 
 **  
 *   
**   
**  *
*** *
***  
**** 
* ** 
*  * 
*    
*   *
* * *
* *  
  *  
  * *
    *
     
   * 
   **
*  **
** **
** * 
 * * 
 * **
 *  *
 ** *
stat (bit number: number of changes): 
{0: 6, 1: 4, 2: 6, 3: 6, 4: 10}
