a-a a-b a-c aaa aab aac aan aao aap aar aay ab- aba abb abc abn abo abp abr aby ac- aca acb acc acn aco acp acr acy an- ana anb anc ann ano anp anr any aoa aob aoc aon aoo aop aor ap- apa apb apc apn apo app apr apy ar- ara arb arc arn aro arp arr ary ay- aya ayc ayn ayo ayp ayr b-p baa bab bac ban bao bap bar bay bba bbb bbc bbn bbo bbp bbr bby bca bcb bcc bcn bco bcp bcr bcy bna bnb bnc bnn bno bnp bnr boa bob boc bon boo bop bor boy bpa bpb bpc bpn bpo bpp bpr bpy bra brb brn bro brp brr bry by- bya byc byn byo byp byr c-- caa cab cac can cao cap car cay cba cbb cbc cbn cbo cbp cbr cby cca ccb ccc ccn cco ccp ccr cn- cna cnb cnc cnn cno cnp cnr cny co- coa cob coc con coo cop cor coy cpa cpb cpc cpn cpo cpp cpr cra crb crc crn cro crp crr cry cya cyb cyc cyn cyo cyp cyr naa nab nac nan nao nap nar nay nba nbb nbc nbn nbo nbp nbr nca ncb ncc ncn nco ncp ncr nna nnb nnc nnn nno nnp no- noa nob noc non noo nop nor noy npa npb npc npn npo npp npr nra nrb nrc nrn nro nrp nrr nry nya nyc nyn nyo nyp nyy oaa oab oac oan oao oap oar ob- oba obb obc obn obo obp obr oby oc- oca ocb occ ocn oco ocp ocr on- ona onb onc onn ono onp onr ony oo- ooa oob ooc oon ooo oop oor op- opa opb opc opn opo opp opr opy or- ora orb orc orn oro orp orr ory oya oyo p-p paa pab pac pan pao pap par pay pba pbb pbc pbn pbo pbp pbr pby pca pcb pcc pcn pco pcp pcr pn- pna pnb pnc pnn pno pnp pnr pny poa pob poc pon poo pop por poy ppa ppb ppc ppn ppo ppp ppr pra prb prc prn pro prp prr pry py- pya pyb pyc pyn pyo pyr ra- raa rab rac ran rao rap rar ray rba rbb rbc rbn rbo rbp rbr rca rcb rcc rcn rco rcp rcr rna rnb rnc rnn rno rnp rnr rny roa rob roc ron roo rop ror roy rpa rpb rpc rpn rpo rpp rpr rra rrb rrc rrn rrp rrr ry- rya ryc ryn ryo ryr ryy yaa yab yac yan yao yap yar yay ybc ybp ybr yby yca ycc yco ycp ycy yna ynn ynp yny yob yoc yon yoo yop yor yoy ypa ypo yra yrc yrn yro yrp yyb yyc yyy