Sentence:  Once , then - for how many years or how <WSD>few</WSD> does not matter - my world was bound round by fences , when I was too small to reach the apple tree bough , to twist my knee over it and pull myself up . 
Meaning of the word marked with <WSD> tags:  a quantifier that can be used with count nouns and is often preceded by `a'; a small but indefinite number