Well I would think you would need at least 2Ns plus the K to march over to the BK without allowing the BBs to cross over the wall of pawns to defend. So I guess sacrifice 3 Knights in such a way as to allow the White king and 2 Ns to cross over and mate the black king. Sounds doable, but not much fun, especially the 50 moves.
Unsolved puzzle :(.

and of course it can be done faster if i try to and it would be much faster if king would not be checked by rooks
Hi everyone!
A friend game me this puzzle, but I can't seem to solve it, He says, "Forced Mate in less than 50" He also says that the 6 rooks are "Walls" and cannot be moved nor captured.
Thanks!