-er a-a a-b a-t aaa aab aae aak aap aar aat ab- aba abb abe abk abp abr abt aea aeb aee aek aep aer aet aka akb ake akk akp akr ap- apa apb ape apk app apr apt ar- ara arb are ark arp arr art at- ata atb ate atp atr att b-p baa bab bae bak bap bar bat bba bbb bbe bbk bbp bbr bbt be- bea beb bee bek bep ber bet bka bkb bke bkk bkp bkr bkt bpa bpb bpe bpp bpr bpt bra brb bre brk brp brr brt bta btb bte btk btp btr btt eaa eab eae eak eap ear eat eba ebb ebe ebk ebp ebr ebt eea eeb eee eek eep eer eet eka ekb eke ekp ekr ekt ep- epa epb epe epp epr ept era erb ere erk erp err ert eta etb ete etk etp etr ett k-t ka- kaa kab kae kak kap kar kat kba kbb kbe kbk kbp kbr ke- kea keb kee kek kep ker ket kkb kke kkk kkp kkr kkt kpa kpe kpk kpp kpr kpt kra krk krp krr krt kta ktb kte ktk ktp ktr ktt p-p paa pab pae pak pap par pat pba pbb pbe pbk pbp pbr pbt pea peb pee pek pep per pet pka pkb pke pkp pkr pkt ppa ppb ppe ppk ppp ppr ppt pra prb pre prk prp prr prt pt- pta ptb pte ptk ptp ptr ptt ra- raa rab rae rak rap rar rat rba rbb rbe rbk rbp rbr rbt re- rea reb ree rek rep rer ret rkb rke rkk rkp rkt rpa rpb rpe rpk rpp rpr rpt rra rrb rrk rrp rrr rrt rta rtb rte rtk rtp rtr rtt taa tab tae tak tap tar tat tba tbb tbe tbk tbp tbr tbt te- tea teb tee tek tep ter tet tka tkb tke tkk tkp tkr tkt tpa tpb tpe tpk tpp tpr tpt tra trb tre trk trp trr trt tta ttb tte ttk ttp ttr ttt