-er bbb bbc bbe bbg bbh bbo bbr bbs bcb bcc bce bcg bch bco bcr bcs be- beb bec bee beg beh beo ber bes bgb bgc bge bgg bgh bgo bgr bgs bhb bhc bhe bhg bhh bho bhr bhs bob boc boe bog boh boo bor bos brb bre brg brh bro brr brs bsb bsc bse bsg bsh bso bsr bss c-- cbb cbc cbe cbg cbh cbo cbr cbs ccb ccc cce ccg cch cco ccr ccs ce- ceb cec cee ceg ceh ceo cer ces cgb cgc cge cgg cgh cgo cgr cgs ch- chb chc che chg chh cho chr chs co- cob coc coe cog coh coo cor cos crb crc cre crg crh cro crr crs csb csc cse csg csh cso csr css ebb ebc ebe ebg ebh ebo ebr ebs ec- ecb ecc ece ecg ech eco ecr ecs eeb eec eee eeg eeo eer ees egb egc ege egg egh ego egr egs ehb ehc ehe ehg ehh eho ehr ehs eo- eob eoc eoe eog eoh eoo eor eos erb erc ere erg erh ero err ers es- esb esc ese esg esh eso esr ess gbc gbe gbg gbh gbo gbr gbs gcb gcc gce gcg gch gco gcr gcs ge- geb gec gee geg geh geo ger ges ggb ggc ggg ggh ggo ggr ggs ghb ghc ghe ghg ghh gho ghr ghs gob goc goe gog goh goo gor gos grb grc gre grg grh gro grr grs gsb gsc gse gsg gso gsr gss hbb hbc hbe hbg hbh hbo hbr hbs hcb hcc hce hcg hch hco hcr hcs he- heb hec hee heg heh heo her hes hgb hgc hge hgg hgh hgo hgr hgs hhb hhc hhe hhg hhh hho hhr hhs hob hoc hoe hog hoh hoo hor hos hr- hrb hrc hre hrg hrh hro hrr hrs hsb hsc hse hsg hsh hsr hss ob- obb obc obe obg obh obo obr obs oc- ocb occ ocg och oco ocr ocs oeb oec oee oeg oeh oeo oer oes ogc oge ogg ogh ogo ogs ohc ohe ohg ohh oho ohr ohs oo- oob ooc oog ooh ooo oor oos or- orb orc ore org orh oro orr ors os- osb osc ose osg osh oso osr oss rbb rbc rbe rbg rbh rbo rbr rbs rcb rcc rce rcg rch rco rcr rcs re- reb rec ree reg reh reo rer res rgb rgc rge rgg rgh rgo rgr rgs rh- rhb rhc rhe rhg rhh rho rhr rhs rob roc roe rog roh roo ror ros rrb rrc rrg rrh rrr rrs rsb rsc rse rsg rsh rso rsr rss sbb sbc sbe sbg sbh sbo sbr sbs scb scc sce scg sch sco scr scs se- seb sec see seg seh seo ser ses sgb sgc sge sgg sgh sgo sgr sgs sh- shb shc she shg shh sho shr shs sob soc soe sog soh soo sor sos sr- srb src sre srg srh sro srr srs ss- ssb ssc sse ssg ssh sso ssr sss