-th fff ffh ffo ffs fft fhf fhh fho fhs fof foh foo fos fot fsf fsh fso fss fst ftf fth fto fts ftt hff hfh hfo hfs hft hhf hhh hho hhs hht hof hoh hoo hos hot hsf hsh hss hst htf hth hto hts htt of- off ofo ofs oft ohf ohh oho ohs oht oo- oof ooh ooo oos oot os- osf osh oso oss ost ot- otf oth oto ots ott sff sfh sfo sfs sft sh- shf shh sho shs sht sof soh soo sos sot ss- ssf ssh sso sss sst stf sth sto sts stt tff tfh tfo tfs tft th- thf thh tho ths tht to- tof toh too tos tot tsf tsh tso tss tst ttf tth tto tts ttt