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

Here is a print-friendly version of this puzzle.

 

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

Thanks,
Steve