-th c-- ccc cch cco ccs cct ch- chc chh cho chs cht co- coc coh coo cos cot csc csh cso css cst ctc cth cto cts ctt hcc hch hco hcs hct hhc hhh hho hhs hht hoc hoh hoo hos hot hsc hsh hss hst htc hth hto hts htt oc- occ och oco ocs oct ohc ohh oho ohs oht oo- ooc ooh ooo oos oot os- osc osh oso oss ost ot- otc oth oto ots ott scc sch sco scs sct sh- shc shh sho shs sht soc soh soo sos sot ss- ssc ssh sso sss sst stc sth sto sts stt tcc tch tco tcs tct th- thc thh tho ths tht to- toc toh too tos tot tsc tsh tso tss tst ttc tth tto tts ttt