tokens: If you actually need to know the position inside the individual quad ( which makes more sense if you want to actually color each quad half-by-half , since the " half-cut " would otherwise vary with the quad 's position ) , then Chris Dodd 's answer is the correct approach .
ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-User_Name I-User_Name O O O O O O O