-er bbb bbe bbh bbo bbr bbs bbx be- beb bee beh beo ber bes bex bhb bhe bhh bho bhr bhs bhx bob boe boh boo bor bos box brb bre brh bro brr brs brx bsb bse bsh bso bsr bss bsx bxb bxo bxx ebb ebe ebh ebo ebr ebs ebx eeb eee eeo eer ees eex ehb ehe ehh eho ehr ehs eo- eob eoe eoh eoo eor eos erb ere erh ero err ers es- esb ese esh eso esr ess esx ex- exe exh exo exr exs exx hbb hbe hbh hbo hbr hbs hbx he- heb hee heh heo her hes hex hhb hhe hhh hho hhr hhs hob hoe hoh hoo hor hos hox hr- hrb hre hrh hro hrr hrs hsb hse hsh hsr hss hsx ob- obb obe obh obo obr obs obx oeb oee oeh oeo oer oes oex ohe ohh oho ohr ohs oo- oob ooh ooo oor oos oox or- orb ore orh oro orr ors orx os- osb ose osh oso osr oss osx ox- oxb oxo oxx rbb rbe rbh rbo rbr rbs rbx re- reb ree reh reo rer res rex rh- rhb rhe rhh rho rhr rhs rob roe roh roo ror ros rox rrb rrh rrr rrs rsb rse rsh rso rsr rss rsx rxr rxs sbb sbe sbh sbo sbr sbs sbx se- seb see seh seo ser ses sex sh- shb she shh sho shr shs sob soe soh soo sor sos sox sr- srb sre srh sro srr srs srx ss- ssb sse ssh sso ssr sss ssx sxs xbe xbr xbx xee xer xes xex xoo xor xos xox xrx xsb xss xxo xxx