a-a a-b a-c aaa aab aac aaj aao aar ab- aba abb abc abj abo abr ac- aca acb acc acj aco acr aja ajb ajc ajj ajo ajr aoa aob aoc aoj aoo aor ar- ara arb arc arj aro arr baa bab bac baj bao bar bba bbb bbc bbo bbr bca bcb bcc bcj bco bcr bja bjc bjj bjr boa bob boc boj boo bor bra brb brj bro brr c-- c-j caa cab cac caj cao car cba cbb cbc cbj cbo cbr cca ccb ccc ccj cco ccr cja cjb cjc cjr co- coa cob coc coj coo cor cra crb crc crj cro crr jaa jab jac jaj jao jar jba jbc jbj jbo jbr jca jcb jcc jco jcr jja jjb jjc jjj jjr joa job joc joj joo jor jra jrb jrc jro jrr oaa oab oac oaj oao oar ob- oba obb obc obj obo obr oc- oca ocb occ ocj oco ocr oja ojb ojc ojo oo- ooa oob ooc ooo oor or- ora orb orc oro orr ra- raa rab rac raj rao rar rba rbb rbc rbo rbr rca rcb rcc rcj rco rcr rja rjc rjr roa rob roc roj roo ror rra rrb rrc rrr