-er -up b-p b-u bbb bbc bbe bbo bbp bbr bbs bbu bcb bcc bce bco bcp bcr bcs bcu be- beb bec bee beo bep ber bes beu bob boc boe boo bop bor bos bou bpb bpc bpe bpo bpp bpr bps bpu brb bre bro brp brr brs bru bsb bsc bse bso bsp bsr bss bsu bub buc bue buo bup bur bus buu c-- cbb cbc cbe cbo cbp cbr cbs cbu ccb ccc cce cco ccp ccr ccs ccu ce- ceb cec cee ceo cep cer ces ceu co- cob coc coe coo cop cor cos cou cpb cpc cpe cpo cpp cpr cps cpu crb crc cre cro crp crr crs cru csb csc cse cso csp csr css csu cub cuc cue cuo cup cur cus cuu ebb ebc ebe ebo ebp ebr ebs ebu ec- ecb ecc ece eco ecr ecs ecu eeb eec eee eeo eep eer ees eo- eob eoc eoe eoo eop eor eos eou ep- epb epc epe epo epp epr eps epu erb erc ere ero erp err ers eru es- esb esc ese eso esp esr ess esu eu- eub euc eue eup eur eus ob- obb obc obe obo obp obr obs obu oc- ocb occ oco ocp ocr ocs ocu oeb oec oee oeo oep oer oes oo- oob ooc ooo oop oor oos op- opb opc ope opo opp opr ops or- orb orc ore oro orp orr ors oru os- osb osc ose oso osp osr oss osu ou- ouc oue ouo oup our ous p-p pbb pbc pbe pbo pbp pbr pbs pbu pcb pcc pce pco pcp pcr pcs pcu peb pec pee peo pep per pes peu pob poc poe poo pop por pos pou ppb ppc ppe ppo ppp ppr pps ppu prb prc pre pro prp prr prs pru ps- psb psc pse pso psp psr pss psu pub puc pue pup pur pus puu rbb rbc rbe rbo rbp rbr rbs rbu rcb rcc rce rco rcp rcr rcs rcu re- reb rec ree reo rep rer res reu rob roc roe roo rop ror ros rou rpb rpc rpe rpo rpp rpr rps rpu rrb rrc rrp rrr rrs rru rsb rsc rse rso rsp rsr rss rsu rub ruc rue ruo rup rur rus ruu sbb sbc sbe sbo sbp sbr sbs sbu scb scc sce sco scp scr scs scu se- seb sec see seo sep ser ses seu sob soc soe soo sop sor sos sou spb spc spe spo spp spr sps spu sr- srb src sre sro srp srr srs ss- ssb ssc sse sso ssp ssr sss ssu sub suc sue suo sup sur sus suu ubb ubc ube ubo ubp ubr ubs ubu ucb ucc uce uco ucp ucr ucs ucu ueb uec uee uep uer ues uob uoc uoe uoo uop uor uos up- upb upc upe upo upp upr ups upu ur- urb urc ure uro urp urr urs uru usb usc use uso usp usr uss usu uuc uue uur uus uuu