b-p bbb bbo bbp bbt bby bob boo bop bot boy bpb bpo bpp bpt bpy btb bto btp btt bty by- byo byp byt ob- obb obo obp obt oby oo- oob ooo oop oot op- opb opo opp opt opy ot- otb oto otp ott oyo p-p pbb pbo pbp pbt pby pob poo pop pot poy ppb ppo ppp ppt pt- ptb pto ptp ptt pty py- pyb pyo pyt tbb tbo tbp tbt to- tob too top tot toy tpb tpo tpp tpt ttb tto ttp ttt tty tyo typ tyt ybp yby yob yoo yop yot yoy ypo yto ytp ytt yyb yyt yyy