n-p-n nnooo no-no no-op nonno nonop nonot notno noto- noton notto onont onoon onoto onpop onpot onto- ontoo ontop ooooo opnto oppon opto- optot optto otono ototo p-n-p po-on po-po ponto poopo popon popop poppo poton potoo potop potto pptnt t-pop t-top tntnt tono- tonto topo- topon topot toppo topto toto- toton totoo totop ttttt