interesting but time comsuming.
1) divide to A1A2A3A4 B1B2B3B4 C1C2C3C4
IF w(A1A2A3A4) = W(B1B2B3B4) simple;
OTHERWISE: assume w(A1A2A3A4) = W(B1B2B3B4)+
2) w(A1A2A3) w(B1B2C1)
IF w(A1A2A3) = w(B1B2C1) ...3)
IF w(A1A2A3) = w(B1B2C1)+ ...3)
IF w(A1A2A3)+ = w(B1B2C1) ...3)