a-a a-b a-i aaa aab aae aai aan aao aap ab- aba abb abe abi abn abo abp aea aeb aee aei aen aeo aep ai- aia aib aie aii ain aio aip an- ana anb ane ani ann ano anp aoa aob aoe aoi aon aoo aop ap- apa apb ape api apn apo app b-p baa bab bae bai ban bao bap bba bbb bbe bbi bbn bbo bbp be- bea beb bee bei ben beo bep bi- bia bib bie bii bin bio bip bna bnb bne bni bnn bno bnp boa bob boe boi bon boo bop bpa bpb bpe bpi bpn bpo bpp eaa eab eae eai ean eao eap eba ebb ebe ebi ebn ebo ebp eea eeb eee een eeo eep eia eib eie eii ein eio eip en- ena enb ene eni enn eno enp eo- eoa eob eoe eoi eon eoo eop ep- epa epb epe epi epn epo epp ia- iaa iab iae iai ian iao iap iba ibb ibe ibi ibn ibo ibp ie- iea iee iei ien iep iia iib iie iii iin iio iip in- ina inb ine ini inn ino inp io- ioa iob ioe ioi ion ioo iop ipa ipb ipe ipi ipn ipo ipp n-i naa nab nae nai nan nao nap nba nbb nbe nbi nbn nbo nbp ne- nea neb nee nei nen neo nep nia nib nie nii nin nio nip nna nnb nne nni nnn nno nnp no- noa nob noe noi non noo nop npa npb npe npi npn npo npp o-i oaa oab oae oai oan oao oap ob- oba obb obe obi obn obo obp oea oeb oee oei oen oeo oep oia oib oie oii oin oio oip on- ona onb one oni onn ono onp oo- ooa oob ooi oon ooo oop op- opa opb ope opi opn opo opp p-p paa pab pae pai pan pao pap pba pbb pbe pbi pbn pbo pbp pea peb pee pei pen peo pep pia pib pie pii pin pio pip pn- pna pnb pne pni pnn pno pnp poa pob poe poi pon poo pop ppa ppb ppe ppi ppn ppo ppp