-er -ey a-a a-b a-c aaa aab aac aae aao aar aay ab- aba abb abc abe abo abr aby ac- aca acb acc ace aco acr acy aea aeb aec aee aeo aer aey aoa aob aoc aoe aoo aor ar- ara arb arc are aro arr ary ay- aya ayc aye ayo ayr baa bab bac bae bao bar bay bba bbb bbc bbe bbo bbr bby bca bcb bcc bce bco bcr bcy be- bea beb bec bee beo ber bey boa bob boc boe boo bor boy bra brb bre bro brr bry by- bya byc bye byo byr c-- caa cab cac cae cao car cay cba cbb cbc cbe cbo cbr cby cca ccb ccc cce cco ccr ce- cea ceb cec cee ceo cer cey co- coa cob coc coe coo cor coy cra crb crc cre cro crr cry cya cyb cyc cye cyo cyr eaa eab eac eae eao ear eba ebb ebc ebe ebo ebr eby ec- eca ecb ecc ece eco ecr eea eeb eec eee eeo eer eey eo- eoa eob eoc eoe eoo eor era erb erc ere ero err ery eya eyc eye eyo eyr oaa oab oac oae oao oar ob- oba obb obc obe obo obr oby oc- oca ocb occ oco ocr oea oeb oec oee oeo oer oey oo- ooa oob ooc ooo oor or- ora orb orc ore oro orr ory oya oye oyo ra- raa rab rac rae rao rar ray rba rbb rbc rbe rbo rbr rca rcb rcc rce rco rcr re- rea reb rec ree reo rer rey roa rob roc roe roo ror roy rra rrb rrc rrr ry- rya ryc rye ryo ryr ryy yaa yab yac yae yao yar yay ybc ybe ybr yby yca ycc yce yco ycy yea yeb yec yee yeo yer yey yob yoc yoe yoo yor yoy yra yrc yre yro yyb yyc yye yyy