-er a-a a-b aaa aab aad aae aak aap aar ab- aba abb abd abe abk abp abr ad- ada adb add ade adk adp adr aea aeb aed aee aek aep aer aka akb akd ake akk akp akr ap- apa apb apd ape apk app apr ar- ara arb ard are ark arp arr b-p baa bab bad bae bak bap bar bba bbb bbd bbe bbk bbp bbr bda bdb bdd bde bdk bdp bdr be- bea beb bed bee bek bep ber bka bkb bke bkk bkp bkr bpa bpb bpd bpe bpp bpr bra brb brd bre brk brp brr daa dab dad dae dak dap dar dba dbb dbd dbe dbk dbp dbr dda ddb ddd dde ddk ddp ddr de- dea deb ded dee dek dep der dka dkb dke dkk dkp dkr dpa dpb dpd dpe dpk dpp dpr dra drb drd dre drk drp drr eaa eab ead eae eak eap ear eba ebb ebd ebe ebk ebp ebr ed- eda edb edd ede edk edp edr eea eeb eed eee eek eep eer eka ekb ekd eke ekp ekr ep- epa epb epd epe epp epr era erb erd ere erk erp err ka- kaa kab kad kae kak kap kar kba kbb kbd kbe kbk kbp kbr kda kdb kde kdk kdp kdr ke- kea keb ked kee kek kep ker kkb kke kkk kkp kkr kpa kpd kpe kpk kpp kpr kra krd krk krp krr p-p paa pab pad pae pak pap par pba pbb pbd pbe pbk pbp pbr pda pdb pdd pde pdk pdp pdr pea peb ped pee pek pep per pka pkb pkd pke pkp pkr ppa ppb ppd ppe ppk ppp ppr pra prb prd pre prk prp prr ra- raa rab rad rae rak rap rar rba rbb rbd rbe rbk rbp rbr rda rdb rdd rde rdp rdr re- rea reb red ree rek rep rer rkb rke rkk rkp rpa rpb rpd rpe rpk rpp rpr rra rrb rrd rrk rrp rrr