a)diagram

1.Bc4-d5     Kh7*g6 
2.Rc7-c4    Bg7-h6 
3.Qd4-d3+  Kg6-g5 
4.Kc3-d4    Kg5-f4 
5.Bf8-c5     Bh6-g7#

b) bRg6->g2

1.Rg2-c2   Kh7-g6 
2.Rc7-b7   Kg6-f5 
3.Qd4-f6+  Kf5-e4 
4.Rb7-b3   Ke4-e3 
5.Bf8-b4    Bg7*f6#

Award: Suomen Tehtäväniekkat No. 1 / 2018, 21.3.2018
The problem shows beautiful play, but I'm disturbed by the black rook on g6.
In the first solution it is not needed and is captured by the wK while
in the second solution it can block bK's square after being moved in the
twinning. My opinion is that the b-form has been composed hastily or
the whole problem has been put together rapidly without caring
for the final result. What I like in this problem is White's play in both solutions
and Black's play in the a-form. But the construction could be something else.
(Judge:Neal Turner)