Solution: 1. Ba2! [2. Kc1 waiting
2. ... Kc3 3. Be5#]
1. ... c1=Q+ 2. Kxc1 waiting
2. ... Kc3 3. Be5#
1. ... c1=R 2. Kxc1 waiting
2. ... Kc3 3. Be5#
1. ... c1=B+ 2. Kxc1 waiting
2. ... Kc3 3. Be5#
1. ... c1=S 2. Kxc1 waiting
2. ... Kc3 3. Be5#
