A compound represented by the formula: wherein A is a C 3-10 cycloalkyl group substituted by 1 to 3 substituents selected from (a) a C 6-14 aryloxy group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, (b) a C 6-14 aryloxy-C 1-6 alkyl group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, (c) a C 7-16 aralkyloxy group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, and (d) a C 7-16 aralkyloxy-C 1-6 alkyl group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, and optionally further substituted by 1 to 3 C 1-6 alkyl groups; L is a bond or a C 1-3 alkylene group optionally substituted by halogen atom(s), Ring D is a ring optionally further substituted by C 1-6 alkyl group(s) optionally substituted by halogen atom(s), n is 1 or 2, X is -O- or -CH 2, and R a and R b are each independently a hydrogen atom or a C 1-6 alkyl group optionally substituted by halogen atom(s), or a salt thereof. A is a C 3-10 cycloalkyl group substituted by 1 to 3 substituents selected from (a) a C 6-14 aryloxy group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, (b) a C 6-14 aryloxy-C 1-6 alkyl group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, (c) a C 7-16 aralkyloxy group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, and (d) a C 7-16 aralkyloxy-C 1-6 alkyl group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, and optionally further substituted by 1 to 3 C 1-6 alkyl groups; (a) a C 6-14 aryloxy group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, (b) a C 6-14 aryloxy-C 1-6 alkyl group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, (c) a C 7-16 aralkyloxy group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, and (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, and (d) a C 7-16 aralkyloxy-C 1-6 alkyl group optionally substituted by 1 to 4 substituents selected from (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, and optionally further substituted by 1 to 3 C 1-6 alkyl groups; (i) a halogen atom, and (ii) an optionally halogenated C 1-6 alkyl group, and optionally further substituted by 1 to 3 C 1-6 alkyl groups; L is a bond or a C 1-3 alkylene group optionally substituted by halogen atom(s), Ring D is a ring optionally further substituted by C 1-6 alkyl group(s) optionally substituted by halogen atom(s), n is 1 or 2, X is -O- or -CH 2, and R a and R b are each independently a hydrogen atom or a C 1-6 alkyl group optionally substituted by halogen atom(s), or a salt thereof.