a-a a-b a-i aaa aab aae aai aam aas ab- aba abb abe abi abm abs aea aeb aee aei aem aes ai- aia aib aie aii aim ais ama amb ame ami amm ams as- asa asb ase asi asm ass baa bab bae bai bam bas bba bbb bbe bbi bbm bbs be- bea beb bee bei bem bes bi- bia bib bie bii bim bis bma bmb bme bmi bmm bms bsa bsb bse bsi bsm bss eaa eab eae eai eam eas eba ebb ebe ebi ebm ebs eea eeb eee eem ees eia eib eie eii eim eis em- ema emb eme emi emm ems es- esa esb ese esi esm ess ia- iaa iab iae iai iam ias iba ibb ibe ibi ibm ibs ie- iea iee iei iem ies iia iib iie iii iim iis im- ima imb ime imi imm ims is- isa isb ise isi ism iss maa mab mae mai mam mas mba mbb mbe mbi mbm mbs mea meb mee mei mem mes mi- mia mib mie mii mim mis mma mmb mme mmi mmm mms msa msb mse msi msm mss saa sab sae sai sam sas sba sbb sbe sbi sbm sbs se- sea seb see sei sem ses sia sib sie sii sim sis sma smb sme smi smm sms ss- ssa ssb sse ssi ssm sss