POLITBUROS

bi bo is it li lo oi op or os pi si so ti to up us ut

bio bis bit boo bop bos bot bro bur bus but its lib lip lis lit lob loo lop lot obi oil oot ops opt orb ors ort our out pis pit piu poi pol poo pot pro psi pst pub pul pur pus put rib rip rob rot rub rut sib sip sir sit sob sol sop sot sou sri sub sup til tip tis too top tor tub tui tup upo ups urb urp uts

bios birl biro bits blip blot blur boil bolo bolt boor boos boot bops bort bots bout brio bris brit broo bros brut burl burp burs bust buts libs lips lisp list lits litu lobo lobs loop loos loot lops lost loti lots loup lour lout lust obis obit obol oils olio oops oots opts opus orbs orts ours oust outs piso pits plot plus pois polo pols pool poor poos port post pots pour pout pros ptui pubs puli puls puri purl purs puts ribs riot rips robs roil root roti rotl roto rots roup rout rubs rust ruts silo silt slip slit slob slop slot slub slur slut soil soli solo soot sorb sori sort soul soup sour spit spot spur stir stob stop stub suit tils tips tirl tiro toil tolu tool topi topo tops tori toro tors tour trio trip trop tubs tuis tups urbs urps