Disclosed is a compound represented by formula (1) or a pharmacologically acceptable salt thereof. (In the formula, A represents a group that is represented by formula (A-1)； R 1a and R 1b may be the same or different and each independently represents a C 1-6 alkyl group which may be substituted by one to three halogen atoms； m and n each independently represents an integer of 0-5； X 1 represents a hydroxyl group or an aminocarbonyl group； Z 1 represents a single bond or the like； and R 2 represents an optionally substituted C 1-6 alkyl group, an optionally substituted C 6-10 aryl group or the like.)
