fff ffn ffo ffp fft fnf fnn fnp fnt fof fon foo fop fot fpn fpo fpp fpt ftf ftn fto ftp ftt nff nfn nfo nfp nft nnf nnn nno nnp nnt no- nof non noo nop not npf npn npo npp npt ntf ntn nto ntp ntt of- off ofn ofo ofp oft on- onf onn ono onp ont oo- oof oon ooo oop oot op- opf opn opo opp opt ot- otf otn oto otp ott p-p pff pfn pfo pfp pft pn- pnf pnn pno pnp pnt pof pon poo pop pot ppf ppn ppo ppp ppt pt- ptf ptn pto ptp ptt tff tfn tfo tfp tft tnf tnn tno tnp tnt to- tof ton too top tot tpf tpn tpo tpp tpt ttf ttn tto ttp ttt