A.B.C.D.
A.A ,B ,C ,...;A ,B ,C ,...B.1,2,3,...;A ,B ,C ,...C.A ,B ,C ,...;1,2,3,...D.1,2,3,...;1,2,3,...
A.Block;Block;B.Block;Insert;C.WBlock;Block;D.Block;Wblock;