W        N    E    
   A      R         
     N         W   I
 A   T              
   R W              
        H A W      R
 R C        T       
     H      E    A  
   N             I C

Code-Doku Joke

How do you prevent a summer cold?

Place each of the letters of A RICH NEWT exactly once in each row, column and 3×3 box. When you have completed the puzzle, the shaded squares will form the punch line of the joke read left to right, then top to bottom.

Difficulty: Extreme

Here is a print-friendly version of this puzzle.

 

Please send responses to my email address is mathrec at this domain

Thanks,
Steve