An object of the invention is to provide compounds of formula (1) or salts thereof which are effective as agricultural and horticultural fungicides. In the formula, R1 represents, for example, a hydroxy group or a cyano group, R2, R3 and R4 are independent of one another and each represent, for example, a hydrogen atom or a halogen atom, R5 represents, for example, a hydrogen atom or a halogen atom, X represents an oxygen atom or a sulfur atom, Y represents, for example, a phenyl group or a pyridyl group, and the bond including the broken line represents a double bond or a single bond.