a-a a-b a-c aaa aab aac aam aao aap ab- aba abb abc abm abo abp ac- aca acb acc acm aco acp ama amb amc amm amo amp aoa aob aoc aom aoo aop ap- apa apb apc apm apo app b-p baa bab bac bam bao bap bba bbb bbc bbm bbo bbp bca bcb bcc bcm bco bcp bma bmb bmc bmm bmo bmp boa bob boc bom boo bop bpa bpb bpc bpm bpo bpp c-- caa cab cac cam cao cap cba cbb cbc cbm cbo cbp cca ccb ccc ccm cco ccp cma cmb cmc cmm cmo cmp co- coa cob coc com coo cop cpa cpb cpc cpm cpo cpp m-o maa mab mac mam mao map mba mbb mbc mbm mbo mbp mc- mca mcb mcc mcm mco mcp mma mmb mmc mmm mmo mmp moa mob moc mom moo mop mpa mpb mpc mpm mpo mpp oaa oab oac oam oao oap ob- oba obb obc obm obo obp oc- oca ocb occ ocm oco ocp om- oma omb omc omm omo omp oo- ooa oob ooc oom ooo oop op- opa opb opc opm opo opp p-p paa pab pac pam pao pap pba pbb pbc pbm pbo pbp pca pcb pcc pcm pco pcp pma pmb pmc pmm pmo pmp poa pob poc pom poo pop ppa ppb ppc ppm ppo ppp