-er a-a a-b aaa aab aae aag aap aar aas ab- aba abb abe abg abp abr abs aea aeb aee aeg aep aer aes ag- aga agb age agg agp agr ags ap- apa apb ape apg app apr aps ar- ara arb are arg arp arr ars as- asa asb ase asg asp asr ass b-p baa bab bae bag bap bar bas bba bbb bbe bbg bbp bbr bbs be- bea beb bee beg bep ber bes bga bgb bge bgg bgp bgr bgs bpa bpb bpe bpg bpp bpr bps bra brb bre brg brp brr brs bsa bsb bse bsg bsp bsr bss eaa eab eae eag eap ear eas eba ebb ebe ebg ebp ebr ebs eea eeb eee eeg eep eer ees ega egb ege egg egp egr egs ep- epa epb epe epg epp epr eps era erb ere erg erp err ers es- esa esb ese esg esp esr ess g-p gaa gab gae gag gap gar gas gba gbe gbg gbp gbr gbs ge- gea geb gee geg gep ger ges gga ggb ggg ggp ggr ggs gpa gpb gpe gpg gpp gpr gps gra grb gre grg grp grr grs gsa gsb gse gsg gsp gsr gss p-p paa pab pae pag pap par pas pba pbb pbe pbg pbp pbr pbs pea peb pee peg pep per pes pga pgb pge pgg pgp pgr pgs ppa ppb ppe ppg ppp ppr pps pra prb pre prg prp prr prs ps- psa psb pse psg psp psr pss ra- raa rab rae rag rap rar ras rba rbb rbe rbg rbp rbr rbs re- rea reb ree reg rep rer res rga rgb rge rgg rgp rgr rgs rpa rpb rpe rpg rpp rpr rps rra rrb rrg rrp rrr rrs rsa rsb rse rsg rsp rsr rss saa sab sae sag sap sar sas sba sbb sbe sbg sbp sbr sbs se- sea seb see seg sep ser ses sga sgb sge sgg sgp sgr sgs spa spb spe spg spp spr sps sr- sra srb sre srg srp srr srs ss- ssa ssb sse ssg ssp ssr sss