Somewhat OT, but it's better if you do vote. In such a scenario I generally vote Libertarian or Green as something of a protest/none-of-the-above vote.

If you can't vote "either way," and you don't vote, then you're effective voting for (or giving the vote to) the combined LeftRight party that you can't bring yourself to vote for.

If you can't be a participant, at least be a Jammer.