bbb bbi bbm bbo bbs bi- bib bii bim bio bis bmb bmi bmm bmo bms bob boi bom boo bos bsb bsi bsm bso bss ibb ibi ibm ibo ibs iib iii iim iio iis im- imb imi imm imo ims io- iob ioi iom ioo ios is- isb isi ism iso iss m-o mbb mbi mbm mbo mbs mi- mib mii mim mio mis mmb mmi mmm mmo mms mob moi mom moo mos msb msi msm mso mss o-i ob- obb obi obm obo obs oib oii oim oio ois om- omb omi omm omo oms oo- oob ooi oom ooo oos os- osb osi osm oso oss sbb sbi sbm sbo sbs sib sii sim sio sis smb smi smm smo sms sob soi som soo sos ss- ssb ssi ssm sso sss