構いません
かまいません · kamaimasen · JLPT N2 · noun
right
構う (kamau) = to bother with; negated = don't bother = it's all right
構う (kamau) means to concern yourself with or fuss over something. Its negative 構いません means you do not bother with it, so it is fine. It answers 'Do you mind?' with 'No, I don't mind.'