-er a-a a-b a-t aaa aab aae aan aap aar aat ab- aba abb abe abn abp abr abt aea aeb aee aen aep aer aet an- ana anb ane ann anp anr ant ap- apa apb ape apn app apr apt ar- ara arb are arn arp arr art at- ata atb ate atn atp atr att b-p baa bab bae ban bap bar bat bba bbb bbe bbn bbp bbr bbt be- bea beb bee ben bep ber bet bna bnb bne bnn bnp bnr bnt bpa bpb bpe bpn bpp bpr bpt bra brb bre brn brp brr brt bta btb bte btn btp btr btt eaa eab eae ean eap ear eat eba ebb ebe ebn ebp ebr ebt eea eeb eee een eep eer eet en- ena enb ene enn enp enr ent ep- epa epb epe epn epp epr ept era erb ere ern erp err ert eta etb ete etn etp etr ett naa nab nae nan nap nar nat nba nbb nbe nbn nbp nbr nbt ne- nea neb nee nen nep ner net nna nnb nne nnn nnp nnt npa npb npe npn npp npr npt nra nrb nre nrn nrp nrr nrt nta ntb nte ntn ntp ntr ntt p-p paa pab pae pan pap par pat pba pbb pbe pbn pbp pbr pbt pea peb pee pen pep per pet pn- pna pnb pne pnn pnp pnr pnt ppa ppb ppe ppn ppp ppr ppt pra prb pre prn prp prr prt pt- pta ptb pte ptn ptp ptr ptt ra- raa rab rae ran rap rar rat rba rbb rbe rbn rbp rbr rbt re- rea reb ree ren rep rer ret rna rnb rnn rnp rnr rnt rpa rpb rpe rpn rpp rpr rpt rra rrb rrn rrp rrr rrt rta rtb rte rtn rtp rtr rtt taa tab tae tan tap tar tat tba tbb tbe tbn tbp tbr tbt te- tea teb tee ten tep ter tet tna tnb tne tnn tnp tnr tnt tpa tpb tpe tpn tpp tpr tpt tra trb tre trn trp trr trt tta ttb tte ttn ttp ttr ttt