a-a a-b a-c aaa aab aac aae aam aas ab- aba abb abc abe abm abs ac- aca acb acc ace acm acs aea aeb aec aee aem aes ama amb amc ame amm ams as- asa asb asc ase asm ass baa bab bac bae bam bas bba bbb bbc bbe bbm bbs bca bcb bcc bce bcm bcs be- bea beb bec bee bem bes bma bmb bmc bme bmm bms bsa bsb bsc bse bsm bss c-- caa cab cac cae cam cas cba cbb cbc cbe cbm cbs cca ccb ccc cce ccm ccs ce- cea ceb cec cee cem ces cma cmb cmc cme cmm cms csa csb csc cse csm css eaa eab eac eae eam eas eba ebb ebc ebe ebm ebs ec- eca ecb ecc ece ecm ecs eea eeb eec eee eem ees em- ema emb emc eme emm ems es- esa esb esc ese esm ess maa mab mac mae mam mas mba mbb mbc mbe mbm mbs mc- mca mcb mcc mce mcm mcs mea meb mec mee mem mes mma mmb mmc mme mmm mms msa msb msc mse msm mss saa sab sac sae sam sas sba sbb sbc sbe sbm sbs sca scb scc sce scm scs se- sea seb sec see sem ses sma smb smc sme smm sms ss- ssa ssb ssc sse ssm sss