a-a a-b aaa aab aap aar aas aay ab- aba abb abp abr abs aby ap- apa apb app apr aps apy ar- ara arb arp arr ars ary as- asa asb asp asr ass asy ay- aya ayp ayr ays b-p baa bab bap bar bas bay bba bbb bbp bbr bbs bby bpa bpb bpp bpr bps bpy bra brb brp brr brs bry bsa bsb bsp bsr bss bsy by- bya byp byr bys p-p paa pab pap par pas pay pba pbb pbp pbr pbs pby ppa ppb ppp ppr pps pra prb prp prr prs pry ps- psa psb psp psr pss psy py- pya pyb pyr pys ra- raa rab rap rar ras ray rba rbb rbp rbr rbs rpa rpb rpp rpr rps rra rrb rrp rrr rrs rsa rsb rsp rsr rss ry- rya ryr rys ryy saa sab sap sar sas say sba sbb sbp sbr sbs sby spa spb spp spr sps spy sr- sra srb srp srr srs sry ss- ssa ssb ssp ssr sss sy- sya syb syp syr sys yaa yab yap yar yas yay ybp ybr ybs yby ypa yps yra yrp yrs ysa ysb ysp ysr yss ysy yyb yys yyy