-er a-a a-b a-t aaa aab aad aae aap aar aat ab- aba abb abd abe abp abr abt ad- ada adb add ade adp adr adt aea aeb aed aee aep aer aet ap- apa apb apd ape app apr apt ar- ara arb ard are arp arr art at- ata atb atd ate atp atr att b-p baa bab bad bae bap bar bat bba bbb bbd bbe bbp bbr bbt bda bdb bdd bde bdp bdr bdt be- bea beb bed bee bep ber bet bpa bpb bpd bpe bpp bpr bpt bra brb brd bre brp brr brt bta btb btd bte btp btr btt daa dab dad dae dap dar dat dba dbb dbd dbe dbp dbr dbt dda ddb ddd dde ddp ddr ddt de- dea deb ded dee dep der det dpa dpb dpd dpe dpp dpr dpt dra drb drd dre drp drr drt dta dtb dtd dte dtp dtr dtt eaa eab ead eae eap ear eat eba ebb ebd ebe ebp ebr ebt ed- eda edb edd ede edp edr edt eea eeb eed eee eep eer eet ep- epa epb epd epe epp epr ept era erb erd ere erp err ert eta etb etd ete etp etr ett p-p paa pab pad pae pap par pat pba pbb pbd pbe pbp pbr pbt pda pdb pdd pde pdp pdr pdt pea peb ped pee pep per pet ppa ppb ppd ppe ppp ppr ppt pra prb prd pre prp prr prt pt- pta ptb ptd pte ptp ptr ptt ra- raa rab rad rae rap rar rat rba rbb rbd rbe rbp rbr rbt rda rdb rdd rde rdp rdr rdt re- rea reb red ree rep rer ret rpa rpb rpd rpe rpp rpr rpt rra rrb rrd rrp rrr rrt rta rtb rtd rte rtp rtr rtt taa tab tad tae tap tar tat tba tbb tbd tbe tbp tbr tbt tda tdb tdd tde tdp tdr tdt te- tea teb ted tee tep ter tet tpa tpb tpd tpe tpp tpr tpt tra trb trd tre trp trr trt tta ttb ttd tte ttp ttr ttt