cccc cccs ccoc ccss ccst cctc cctt coco coct coos coot cosc coso coss cost cotc coto cots cott cscc csco cscs csos csot cstc csto csts ctos ctot ctsc ctss ctts occc occt ocos oct- octo octs oooo ooos oost oots oscc osco osoo osos osso ostc osts oto- otoo otos otso otto otts s-os sccc sccs scct scoo scot scsc scso scst sctc scto scts soco socs soos soot soso soss sost sotc soto sots sscc sscs ssoc ssot sssc ssss sstc ssts stcc stcs stoo stos stot stss sttc tccc tcos tctc tcts toco toos toot tosc toso toss tost totc toto tots tott tscc tsos tsst tstc tsts ttss tttt