-ic a-a a-b a-c a-i aaa aab aac aai aao aas aau ab- aba abb abc abi abo abs abu ac- aca acb acc aci aco acs acu ai- aia aib aic aii aio ais aiu aoa aob aoc aoi aoo aos aou as- asa asb asc asi aso ass asu au- aua aub auc aui auo aus b-u baa bab bac bai bao bas bau bba bbb bbc bbi bbo bbs bbu bca bcb bcc bci bco bcs bcu bi- bia bib bic bii bio bis biu boa bob boc boi boo bos bou bsa bsb bsc bsi bso bss bsu bua bub buc bui buo bus buu c-- caa cab cac cai cao cas cau cba cbb cbc cbi cbo cbs cbu cca ccb ccc cci cco ccs ccu ci- cia cib cic cii cio cis ciu co- coa cob coc coi coo cos cou csa csb csc csi cso css csu cua cub cuc cui cuo cus cuu ia- iaa iab iac iai iao ias iau iba ibb ibc ibi ibo ibs ibu ica icb icc ici ico ics icu iia iib iic iii iio iis iiu io- ioa iob ioc ioi ioo ios iou is- isa isb isc isi iso iss isu iu- iua iub iuc iui ius o-i oaa oab oac oai oao oas oau ob- oba obb obc obi obo obs obu oc- oca ocb occ oci oco ocs ocu oia oib oic oii oio ois oiu oo- ooa oob ooc ooi ooo oos os- osa osb osc osi oso oss osu ou- oua ouc oui ouo ous saa sab sac sai sao sas sau sba sbb sbc sbi sbo sbs sbu sca scb scc sci sco scs scu sia sib sic sii sio sis siu soa sob soc soi soo sos sou ss- ssa ssb ssc ssi sso sss ssu sua sub suc sui suo sus suu ua- uaa uab uac uai uao uas uau uba ubb ubc ubi ubo ubs ubu uca ucb ucc uci uco ucs ucu uia uib uic uii uio uis uiu uoa uob uoc uoo uos usa usb usc usi uso uss usu uua uuc uus uuu