Because you're using double-quotes (""), you need to backslash the backslash. :) If you used single-quotes ('') like 'a\+b', you'll be just fine.

The lesson here is to use the minimal quoting mechanism. Unless you're interpolating variables, use ''. If you're interpolating variables, remember that everything is interpolated.

------
/me wants to be the brightest bulb in the chandelier!