
Solution
1.B*4f

if 2.R8c, 3.Bx1c+.
1.B*4f
if 2.R8c, 3.Bx1c+.
1.R1b+
1.S*4b 2.+Bx4b 3.+R2a
1.P*5d
if 2.Sx5d, 3.P*5e.
1.Bx6d
if 2.Gx6d, 3.Nx5c+.
1.+Rx1c 2.Kx1c 3.L*1d 4.Kx1d 5.G*2d
1.+B1c 2.Kx1c 3.B*3a 4.K1b 5.B2b+
1.P*2d
there is no way for White to prevent P2c+ on the next move.
1.P*3c
if 2.Bx3c, 3.Rx2a+. if 2.Gx3c, 3.P*2c
1.G*2b 2.Sx2b 3.G*4b