-er a-a a-b aaa aab aad aae aan aap aar ab- aba abb abd abe abn abp abr ad- ada adb add ade adn adp adr aea aeb aed aee aen aep aer an- ana anb and ane ann anp anr ap- apa apb apd ape apn app apr ar- ara arb ard are arn arp arr b-p baa bab bad bae ban bap bar bba bbb bbd bbe bbn bbp bbr bda bdb bdd bde bdp bdr be- bea beb bed bee ben bep ber bna bnb bnd bne bnn bnp bnr bpa bpb bpd bpe bpn bpp bpr bra brb brd bre brn brp brr daa dab dad dae dan dap dar dba dbb dbd dbe dbn dbp dbr dda ddb ddd dde ddn ddp ddr de- dea deb ded dee den dep der dna dnb dnd dne dnn dnp dnr dpa dpb dpd dpe dpn dpp dpr dra drb drd dre drn drp drr eaa eab ead eae ean eap ear eba ebb ebd ebe ebn ebp ebr ed- eda edb edd ede edn edp edr eea eeb eed eee een eep eer en- ena enb end ene enn enp enr ep- epa epb epd epe epn epp epr era erb erd ere ern erp err naa nab nad nae nan nap nar nba nbb nbd nbe nbn nbp nbr nda ndb ndd nde ndn ndp ndr ne- nea neb ned nee nen nep ner nna nnb nne nnn nnp npa npb npd npe npn npp npr nra nrb nrd nre nrn nrp nrr p-p paa pab pad pae pan pap par pba pbb pbd pbe pbn pbp pbr pda pdb pdd pde pdn pdp pdr pea peb ped pee pen pep per pn- pna pnb pnd pne pnn pnp pnr ppa ppb ppd ppe ppn ppp ppr pra prb prd pre prn prp prr ra- raa rab rad rae ran rap rar rba rbb rbd rbe rbn rbp rbr rda rdb rdd rde rdn rdp rdr re- rea reb red ree ren rep rer rna rnb rnd rnn rnp rnr rpa rpb rpd rpe rpn rpp rpr rra rrb rrd rrn rrp rrr