obr obt oc- oca ocb occ ocf ocg oci ocl ocn oco ocr oct of- ofa ofb ofc off ofg ofi ofl ofn ofo ofr oft oga ogc ogf ogg ogi ogl ogn ogo ogt oia oib oic oif oii oil oin oio oir oit ola olb olc olf olg oli oll oln olo olt on- ona onb onc onf ong oni onl onn ono onr ont oo- ooa oob ooc oof oog ooi ool oon ooo oor oot or- ora orb orc orf org ori orl orn oro orr ort ot- ota otb otc otf otg oti otl otn oto otr ott ra- raa rab rac raf rag rai ral ran rao rar rat rba rbb rbc rbf rbg rbi rbl rbn rbo rbr rbt rca rcb rcc rcf rcg rci rcl rcn rco rcr rct rfa rfb rfc rff rfg rfi rfl rfn rfo rfr rft rga rgb rgc rgf rgg rgi rgn rgo rgr rgt ria rib ric rif rig rii ril rin rio rir rit rla rlc rlf rlg rli rll rln rlo rlr rlt rna rnb rnc rng rni rnn rno rnr rnt roa rob roc rof rog roi rol ron roo ror rot rra rrb rrc rrf rrg rri rrl rrn rrr rrt rta rtb rtc rtf rtg rti rtl rtn rto rtr rtt taa tab tac taf tag tai tal tan tao tar tat tba tbb tbc tbf tbg tbi tbl tbn tbo tbr tbt tca tcb tcc tcf tcg tci tcl tcn tco tcr tct tfa tfb tfc tff tfg tfi tfl tfn tfo tfr tft tga tgb tgc tgf tgg tgi tgl tgn tgo tgr tgt tia tib tic tif tig tii til tin tio tir tit tla tlc tlf tlg tli tll tln tlo tlr tlt tna tnb tnc tnf tng tni tnl tnn tno tnr tnt to- toa tob toc tof tog toi tol ton too tor tot tra trb trc trf trg tri trl trn tro trr trt tta ttb ttc ttf ttg tti ttl ttn tto ttr ttt