-er a-a a-b a-c aaa aab aac aae aah aan aao aap aar ab- aba abb abc abe abh abn abo abp abr ac- aca acb acc ace ach acn aco acp acr aea aeb aec aee aeh aen aeo aep aer aha ahb ahc ahe ahh ahn aho ahp ahr an- ana anb anc ane anh ann ano anp anr aoa aob aoc aoe aoh aon aoo aop aor ap- apa apb apc ape aph apn apo app apr ar- ara arb arc are arh arn aro arp arr b-p baa bab bac bae bah ban bao bap bar bba bbb bbc bbe bbh bbn bbo bbp bbr bca bcb bcc bce bch bcn bco bcp bcr be- bea beb bec bee beh ben beo bep ber bha bhb bhc bhe bhh bho bhp bhr bna bnb bnc bne bnn bno bnp bnr boa bob boc boe boh bon boo bop bor bpa bpb bpc bpe bph bpn bpo bpp bpr bra brb bre brh brn bro brp brr c-- caa cab cac cae cah can cao cap car cba cbb cbc cbe cbh cbn cbo cbp cbr cca ccb ccc cce cch ccn cco ccp ccr ce- cea ceb cec cee ceh cen ceo cep cer ch- cha chb chc che chh chn cho chp chr cn- cna cnb cnc cne cnh cnn cno cnp cnr co- coa cob coc coe coh con coo cop cor cpa cpb cpc cpe cph cpn cpo cpp cpr cra crb crc cre crh crn cro crp crr eaa eab eac eae eah ean eao eap ear eba ebb ebc ebe ebh ebn ebo ebp ebr ec- eca ecb ecc ece ech ecn eco ecr eea eeb eec eee een eeo eep eer eha ehb ehc ehe ehh ehn eho ehp ehr en- ena enb enc ene enh enn eno enp enr eo- eoa eob eoc eoe eoh eon eoo eop eor ep- epa epb epc epe eph epn epo epp epr era erb erc ere erh ern ero erp err haa hab hac hae hah han hao hap har hba hbb hbc hbe hbh hbn hbo hbp hbr hca hcb hcc hce hch hcn hco hcp hcr he- hea heb hec hee heh hen heo hep her hha hhb hhc hhe hhh hhn hho hhp hhr hna hnb hnc hne hnh hnn hno hoa hob hoc hoe hoh hon hoo hop hor hpa hpb hpc hpe hph hpn hpo hpp hpr hr- hra hrb hrc hre hrh hrn hro hrp hrr naa nab nac nae nah nan nao nap nar nba nbb nbc nbe nbn nbo nbp nbr nca ncb ncc nce nch ncn nco ncp ncr ne- nea neb nec nee neh nen neo nep ner nha nhb nhc nhe nhh nhn nhp nhr nna nnb nnc nne nnh nnn nno nnp no- noa nob noc noe noh non noo nop nor npa npb npc npe nph npn npo npp npr nra nrb nrc nre nrn nro nrp nrr oaa oab oac oae oah oan oao oap oar ob- oba obb obc obe obh obn obo obp obr oc- oca ocb occ och ocn oco ocp ocr oea oeb oec oee oeh oen oeo oep oer oha ohc ohe ohh ohn oho ohp ohr on- ona onb onc one onh onn ono onp onr oo- ooa oob ooc ooh oon ooo oop oor op- opa opb opc ope oph opn opo opp opr or- ora orb orc ore orh orn oro orp orr p-p paa pab pac pae pah pan pao pap par pba pbb pbc pbe pbn pbo pbp pbr pca pcb pcc pce pch pcn pco pcp pcr pea peb pec pee peh pen peo pep per pha phb phc phe phn pho php phr pn- pna pnb pnc pne pnh pnn pno pnp pnr poa pob poc poe poh pon poo pop por ppa ppb ppc ppe pph ppn ppo ppp ppr pra prb prc pre prh prn pro prp prr ra- raa rab rac rae rah ran rao rap rar rba rbb rbc rbe rbh rbn rbo rbp rbr rca rcb rcc rce rch rcn rco rcp rcr re- rea reb rec ree reh ren reo rep rer rh- rha rhb rhc rhe rhh rhn rho rhp rhr rna rnb rnc rnh rnn rno rnp rnr roa rob roc roe roh ron roo rop ror rpa rpb rpc rpe rph rpn rpo rpp rpr rra rrb rrc rrh rrn rrp rrr