a-a a-c aaa aac aar aas aau aax ac- aca acc acr acs acu acx ar- ara arc arr ars aru arx as- asa asc asr ass asu asx au- aua auc aur aus aux ax- axa axr axs axx c-- caa cac car cas cau cax cca ccc ccr ccs ccu ccx cra crc crr crs cru crx csa csc csr css csu csx cua cuc cur cus cuu cxc cxr cxs cxx ra- raa rac rar ras rau rax rca rcc rcr rcs rcu rcx rra rrc rrr rrs rru rsa rsc rsr rss rsu rsx rua ruc rur rus ruu rux rxr rxs saa sac sar sas sau sax sca scc scr scs scu scx sr- sra src srr srs srx ss- ssa ssc ssr sss ssu ssx sua suc sur sus suu sux sxc sxs sxu ua- uaa uac uar uas uau uca ucc ucr ucs ucu ur- ura urc urr urs uru urx usa usc usr uss usu usx uua uuc uur uus uuu uxc uxr uxu xaa xac xar xas xau xcr xcx xrc xrx xsa xsc xss xus xxx