1...Ka4 2.Sc6 ~ 3.R*b4#,

1.Kc1? A b3!,

1.Sd7! zz. Ka6 (Ka4 ) 2.Sc5+ C Ka5 3.Kc1 A zz. b3 4.Bc3# B,

1...b3 2.K*b3 ~ 3.Bc3+ B Ka6 4.Sc5 # C, 2...Ka6 3.Sc5 + C Ka5 4.Bc3# B.