-up b-p b-u bbb bbo bbp bbt bbu bob boo bop bot bou bpb bpo bpp bpt bpu btb bto btp btt btu bub buo bup but buu ob- obb obo obp obt obu oo- oob ooo oop oot op- opb opo opp opt ot- otb oto otp ott otu ou- ouo oup out p-p pbb pbo pbp pbt pbu pob poo pop pot pou ppb ppo ppp ppt ppu pt- ptb pto ptp ptt ptu pub pup put puu tbb tbo tbp tbt tbu to- tob too top tot tou tpb tpo tpp tpt tpu ttb tto ttp ttt ttu tub tuo tup tut tuu ubb ubo ubp ubt ubu uob uoo uop uot up- upb upo upp upt upu utb uto utp utt utu uut uuu