-al -ol a-a a-b aaa aab aal aao aas ab- aba abb abl abo abs al- ala alb all alo als aoa aob aol aoo aos as- asa asb asl aso ass baa bab bal bao bas bba bbb bbl bbo bbs bla blb bll blo bls boa bob bol boo bos bsa bsb bsl bso bss la- laa lab lal lao las lba lbb lbl lbo lbs lla llb lll llo lls loa lob lol loo los lsa lsb lsl lso lss oaa oab oal oao oas ob- oba obb obl obo obs ola olb oll olo ols oo- ooa oob ool ooo oos os- osa osb osl oso oss saa sab sal sao sas sba sbb sbl sbo sbs sla slb sll slo sls soa sob sol soo sos ss- ssa ssb ssl sso sss