Smouthered mate is also possible! (Stupid Puzzle!) But it's mate in 5 ... 

3 Na6+ Ka8 (3...Kc8 4 Qc7#) 4 Qb8+ Rxb8 5 Nc7#

In a real game if you "only" see the smouthered mate, just play it. Don't look for a faster way!

Good!

Is 3. Na6++ wrong?

i see

NOT THAT HARD

very nice thankyou

easy peasy

nice!

no option for black king...

i think there is also alternate solution.

At last I got one with no cheating - must be easy!

nice 

hmm:)

amazing

easy

Good puzzle.

very nice puzzle, hope i get a chance to use it in a real game

smothered mate 2! me :)

3 ka6++ is smarter