-er a-a a-b a-t aaa aab aae aan aao aap aar aat ab- aba abb abe abn abo abp abr abt aea aeb aee aen aeo aep aer aet an- ana anb ane ann ano anp anr ant aoa aob aoe aon aoo aop aor aot ap- apa apb ape apn apo app apr apt ar- ara arb are arn aro arp arr art at- ata atb ate atn ato atp atr att b-p baa bab bae ban bao bap bar bat bba bbb bbe bbn bbo bbp bbr bbt be- bea beb bee ben beo bep ber bet bna bnb bne bnn bno bnp bnr bnt boa bob boe bon boo bop bor bot bpa bpb bpe bpn bpo bpp bpr bpt bra brb bre brn bro brp brr brt bta btb bte btn bto btp btr btt eaa eab eae ean eao eap ear eat eba ebb ebe ebn ebo ebp ebr ebt eea eeb eee een eeo eep eer eet en- ena enb ene enn eno enp enr ent eo- eoa eob eoe eon eoo eop eor eot ep- epa epb epe epn epo epp epr ept era erb ere ern ero erp err ert eta etb ete etn eto etp etr ett naa nab nae nan nao nap nar nat nba nbb nbe nbn nbo nbp nbr nbt ne- nea neb nee nen neo nep ner net nna nnb nne nnn nno nnp nnt no- noa nob noe non noo nop nor not npa npb npe npn npo npp npr npt nra nrb nre nrn nro nrp nrr nrt nta ntb nte ntn nto ntp ntr ntt oaa oab oae oan oao oap oar oat ob- oba obb obe obn obo obp obr obt oea oeb oee oen oeo oep oer oet on- ona onb one onn ono onp onr ont oo- ooa oob oon ooo oop oor oot op- opa opb ope opn opo opp opr opt or- ora orb ore orn oro orp orr ort ot- ota otb ote otn oto otp otr ott p-p paa pab pae pan pao pap par pat pba pbb pbe pbn pbo pbp pbr pbt pea peb pee pen peo pep per pet pn- pna pnb pne pnn pno pnp pnr pnt poa pob poe pon poo pop por pot ppa ppb ppe ppn ppo ppp ppr ppt pra prb pre prn pro prp prr prt pt- pta ptb pte ptn pto ptp ptr ptt ra- raa rab rae ran rao rap rar rat rba rbb rbe rbn rbo rbp rbr rbt re- rea reb ree ren reo rep rer ret rna rnb rnn rno rnp rnr rnt roa rob roe ron roo rop ror rot rpa rpb rpe rpn rpo rpp rpr rpt rra rrb rrn rrp rrr rrt rta rtb rte rtn rto rtp rtr rtt taa tab tae tan tao tap tar tat tba tbb tbe tbn tbo tbp tbr tbt te- tea teb tee ten teo tep ter tet tna tnb tne tnn tno tnp tnr tnt to- toa tob toe ton too top tor tot tpa tpb tpe tpn tpo tpp tpr tpt tra trb tre trn tro trp trr trt tta ttb tte ttn tto ttp ttr ttt