-er a-a a-b aaa aab aad aae aap aar aas ab- aba abb abd abe abp abr abs ad- ada adb add ade adp adr ads aea aeb aed aee aep aer aes ap- apa apb apd ape app apr aps ar- ara arb ard are arp arr ars as- asa asb asd ase asp asr ass b-p baa bab bad bae bap bar bas bba bbb bbd bbe bbp bbr bbs bda bdb bdd bde bdp bdr bds be- bea beb bed bee bep ber bes bpa bpb bpd bpe bpp bpr bps bra brb brd bre brp brr brs bsa bsb bsd bse bsp bsr bss daa dab dad dae dap dar das dba dbb dbd dbe dbp dbr dbs dda ddb ddd dde ddp ddr dds de- dea deb ded dee dep der des dpa dpb dpd dpe dpp dpr dps dra drb drd dre drp drr drs dsa dsb dsd dse dsp dsr dss eaa eab ead eae eap ear eas eba ebb ebd ebe ebp ebr ebs ed- eda edb edd ede edp edr eds eea eeb eed eee eep eer ees ep- epa epb epd epe epp epr eps era erb erd ere erp err ers es- esa esb esd ese esp esr ess p-p paa pab pad pae pap par pas pba pbb pbd pbe pbp pbr pbs pda pdb pdd pde pdp pdr pds pea peb ped pee pep per pes ppa ppb ppd ppe ppp ppr pps pra prb prd pre prp prr prs ps- psa psb psd pse psp psr pss ra- raa rab rad rae rap rar ras rba rbb rbd rbe rbp rbr rbs rda rdb rdd rde rdp rdr rds re- rea reb red ree rep rer res rpa rpb rpd rpe rpp rpr rps rra rrb rrd rrp rrr rrs rsa rsb rsd rse rsp rsr rss saa sab sad sae sap sar sas sba sbb sbd sbe sbp sbr sbs sda sdb sdd sde sdp sdr sds se- sea seb sed see sep ser ses spa spb spd spe spp spr sps sr- sra srb srd sre srp srr srs ss- ssa ssb ssd sse ssp ssr sss