b-u bbb bbl bbn bbs bbu blb bll bln bls blu bnb bnl bnn bns bnu bsb bsl bsn bss bsu bub bul bun bus buu lbb lbl lbs lbu llb lll lln lls llu lnb lnl lnn lns lnu lsb lsl lsn lss lsu lub lul lun lus luu nbb nbl nbn nbs nbu nlb nll nln nls nlu nnb nnl nnn nns nnu nsb nsl nsn nss nsu nub nul nun nus nuu sbb sbl sbn sbs sbu slb sll sln sls slu snb snl snn sns snu ss- ssb ssl ssn sss ssu sub sul sun sus suu ubb ubl ubn ubs ubu ulb ull uln uls ulu un- unb unl unn uns unu usb usl usn uss usu uun uus uuu