c-- ccc cch cco ccp ccs ch- chc chh cho chp chs co- coc coh coo cop cos cpc cph cpo cpp cps csc csh cso csp css hcc hch hco hcp hcs hhc hhh hho hhp hhs hoc hoh hoo hop hos hpc hph hpo hpp hps hsc hsh hsp hss oc- occ och oco ocp ocs ohc ohh oho ohp ohs oo- ooc ooh ooo oop oos op- opc oph opo opp ops os- osc osh oso osp oss p-p pcc pch pco pcp pcs phc pho php phs poc poh poo pop pos ppc pph ppo ppp pps ps- psc psh pso psp pss scc sch sco scp scs sh- shc shh sho shp shs soc soh soo sop sos spc sph spo spp sps ss- ssc ssh sso ssp sss