-er eee eem eep eer eet eex eie eii eim eip eir eit eix em- eme emi emm emp emr emt emx ep- epe epi epm epp epr ept epx ere eri erm erp err ert ete eti etm etp etr ett etx ex- exe exi exp exr ext exx ie- iee iei iem iep ier iet iex iie iii iim iip iir iit iix im- ime imi imm imp imt imx ipe ipi ipm ipp ipr ipt ipx ir- ire iri irm irp irr irt irx ite iti itm itp itt itx ixe ixi m-r mee mei mem mep mer met mex mi- mie mii mim mip mir mit mix mme mmi mmm mmp mmr mmt mmx mpe mpi mpm mpp mpr mpt mpx mre mri mrm mrp mrr mrt mrx mte mti mtm mtp mtr mtt mtx mxi mxp mxr p-p pee pei pem pep per pet pex pie pii pim pip pir pit pix pme pmi pmm pmp pmr pmt pmx ppe ppi ppm ppp ppr ppt ppx pre pri prm prp prr prt prx pt- pte pti ptm ptp ptr ptt ptx pxe pxm pxr pxt re- ree rei rem rep rer ret rex rie rii rim rip rir rit rix rme rmi rmm rmp rmr rmt rmx rpe rpi rpm rpp rpr rpt rpx rri rrm rrp rrr rrt rte rti rtm rtp rtr rtt rtx rxp rxr t-x te- tee tei tem tep ter tet tex tie tii tim tip tir tit tix tme tmi tmm tmp tmr tmt tmx tpe tpi tpm tpp tpr tpt tpx tre tri trm trp trr trt trx tte tti ttm ttp ttr ttt ttx txe txi txt xee xem xep xer xet xex xie xii xit xix xmi xmm xmp xmr xmt xmx xpe xpm xpp xpt xrt xrx xti xtm xtp xtr xtx xxi xxp xxx