a-a a-b a-i aaa aab aai aam aas ab- aba abb abi abm abs ai- aia aib aii aim ais ama amb ami amm ams as- asa asb asi asm ass baa bab bai bam bas bba bbb bbi bbm bbs bi- bia bib bii bim bis bma bmb bmi bmm bms bsa bsb bsi bsm bss ia- iaa iab iai iam ias iba ibb ibi ibm ibs iia iib iii iim iis im- ima imb imi imm ims is- isa isb isi ism iss maa mab mai mam mas mba mbb mbi mbm mbs mi- mia mib mii mim mis mma mmb mmi mmm mms msa msb msi msm mss saa sab sai sam sas sba sbb sbi sbm sbs sia sib sii sim sis sma smb smi smm sms ss- ssa ssb ssi ssm sss