-th h-i hhh hhi hhs hht hhy hih hii his hit hix hsh hsi hss hst hsx hsy hth hti hts htt htx hty hy- hyh hyi hys hyt hyy ihh ihi ihs iht ihy iih iii iis iit iix is- ish isi iss ist isy ith iti its itt itx ity ixi ixy iys iyt iyy sh- shh shi shs sht shy sih sii sis sit six ss- ssh ssi sss sst ssx sth sti sts stt stx sty sxi sxs sxt sy- syh syi sys syt syx t-x th- thh thi ths tht thx thy tih tii tis tit tix tiy tsh tsi tss tst tsx tsy tth tti tts ttt ttx tty txi txs txt tys tyt xht xii xis xit xix xsi xss xst xti xts xtx xty xxi xxx xxy xyy yhi yhs yht yih yii yis yit ysi yss yst ysy yth yts ytt yxy yys yyt yyy