A compound represented by the formula: wherein ring A is a benzene ring or a pyridine ring, each of which is optionally substituted by 1 to 3 substituents selected from a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group; Y is an oxygen atom, a sulfur atom or a nitrogen atom; X is -CH(R 5)-O- or -CH(R 5)-NH-, wherein R 5 is (i) a C 1-6 alkyl group, (ii) a C 3-10 cycloalkyl group optionally substituted by 1 to 3 substituents selected from (a) an oxo group, (b) a hydroxy group, and (c) a C 1-3 alkylenedioxy, (iii) a C 6-14 aryl group, or (iv) a 5- or 6-membered monocyclic nonaromatic heterocyclic group; R 1 is a C 1-6 alkyl group optionally substituted by 1 to 3 hydroxy groups; a C 3-10 cycloalkyl group; a C 6-14 aryl group optionally substituted by 1 to 3 substituents selected from (i) a halogen atom, (ii) a C 1-6 alkyl group optionally substituted by 1 to 3 halogen atoms, (iii) a C 1-6 alkoxy group optionally substituted by 1 to 3 substituents selected from (a) a halogen atom, (b) a C 1-6 alkylthio group, (c) a C 1-6 alkylsulfinyl group, and (d) a C 1-6 alkylsulfonyl group, (vi) a C 1-6 alkylsulfonyl group, and (v) a carbamoyl group; a 4- to 12-membered heterocyclic group optionally substituted by 1 to 3 substituents selected from (i) a halogen atom, (ii) a C 1-6 alkyl group, and (iii) a C 1-6 alkoxy group optionally substituted by 1 to 3 substituents selected from (a) a C 1-6 alkoxy group, (b) a hydroxy group, and (c) a 5- or 6-membered monocyclic nonaromatic heterocyclic group optionally substituted by 1 or 2 oxo groups; a C 1-6 alkyl-carbonyl group; or a C 3-10 cycloalkyl-carbonyl group; R 2 is a C 1-6 alkyl group optionally substituted by 1 to 3 substituents selected from (i) a C 1-6 alkoxy group, (ii) a C 1-6 alkylthio group, (iii) a C 1-6 alkylsulfinyl group, and (iv) a C 1-6 alkylsulfonyl group, or a C 3-10 cycloalkyl group; R 3 is -NR 7 -CH 2 -CH (R 11) -COOH wherein R 7 is a hydrogen atom, or a C 1-6 alkyl group, and R 11 is a hydrogen atom, or a hydroxy group, or a salt thereof. a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group; -CH(R 5)-O- or -CH(R 5)-NH-, (i) a C 1-6 alkyl group, (ii) a C 3-10 cycloalkyl group optionally substituted by 1 to 3 substituents selected from (a) an oxo group, (b) a hydroxy group, and (c) a C 1-3 alkylenedioxy, (a) an oxo group, (b) a hydroxy group, and (c) a C 1-3 alkylenedioxy, (iii) a C 6-14 aryl group, or (iv) a 5- or 6-membered monocyclic nonaromatic heterocyclic group; a C 1-6 alkyl group optionally substituted by 1 to 3 hydroxy groups; a C 3-10 cycloalkyl group; a C 6-14 aryl group optionally substituted by 1 to 3 substituents selected from (i) a halogen atom, (ii) a C 1-6 alkyl group optionally substituted by 1 to 3 halogen atoms, (iii) a C 1-6 alkoxy group optionally substituted by 1 to 3 substituents selected from (a) a halogen atom, (b) a C 1-6 alkylthio group, (c) a C 1-6 alkylsulfinyl group, and (d) a C 1-6 alkylsulfonyl group, (vi) a C 1-6 alkylsulfonyl group, and (v) a carbamoyl group; (i) a halogen atom, (ii) a C 1-6 alkyl group optionally substituted by 1 to 3 halogen atoms, (iii) a C 1-6 alkoxy group optionally substituted by 1 to 3 substituents selected from (a) a halogen atom, (b) a C 1-6 alkylthio group, (c) a C 1-6 alkylsulfinyl group, and (d) a C 1-6 alkylsulfonyl group, (a) a halogen atom, (b) a C 1-6 alkylthio group, (c) a C 1-6 alkylsulfinyl group, and (d) a C 1-6 alkylsulfonyl group, (vi) a C 1-6 alkylsulfonyl group, and (v) a carbamoyl group; a 4- to 12-membered heterocyclic group optionally substituted by 1 to 3 substituents selected from (i) a halogen atom, (ii) a C 1-6 alkyl group, and (iii) a C 1-6 alkoxy group optionally substituted by 1 to 3 substituents selected from (a) a C 1-6 alkoxy group, (b) a hydroxy group, and (c) a 5- or 6-membered monocyclic nonaromatic heterocyclic group optionally substituted by 1 or 2 oxo groups; (i) a halogen atom, (ii) a C 1-6 alkyl group, and (iii) a C 1-6 alkoxy group optionally substituted by 1 to 3 substituents selected from (a) a C 1-6 alkoxy group, (b) a hydroxy group, and (c) a 5- or 6-membered monocyclic nonaromatic heterocyclic group optionally substituted by 1 or 2 oxo groups; (a) a C 1-6 alkoxy group, (b) a hydroxy group, and (c) a 5- or 6-membered monocyclic nonaromatic heterocyclic group optionally substituted by 1 or 2 oxo groups; a C 1-6 alkyl-carbonyl group; or a C 3-10 cycloalkyl-carbonyl group; a C 1-6 alkyl group optionally substituted by 1 to 3 substituents selected from (i) a C 1-6 alkoxy group, (ii) a C 1-6 alkylthio group, (iii) a C 1-6 alkylsulfinyl group, and (iv) a C 1-6 alkylsulfonyl group, or (i) a C 1-6 alkoxy group, (ii) a C 1-6 alkylthio group, (iii) a C 1-6 alkylsulfinyl group, and (iv) a C 1-6 alkylsulfonyl group, or a C 3-10 cycloalkyl group; a hydrogen atom, or a C 1-6 alkyl group, and a hydrogen atom, or a hydroxy group,