Correct answer: a8Q1...Ng2/Ng6/Nh3/Nh5/Nfe2/Nd5 2.Ng6# 1...Nde2/Nf3/Nc6+/Nb5 2.Nec6#/Nbc6# 1...Nde6 2.Nec6# 1...Nc2 2.Nbc6#