Glycine compound

A compound represented by the formula (I) or a salt thereof:

• wherein
• R1 is H or lower alkyl which may be substituted with halogen,
• R2 is halogen,
• R3 and R4 are the same as or different from each other, and are H or halogen,
• m is 0, 1, 2, 3, or 4,
• Y1 and Y2 are both N,
• X is Z—,
• Z is
• R21, R22, R23, R24, R25 and R26 are H, Y4 is N or CRY41, Y5 is N or CRY51, RY41, RY51, and RG32 are H, halogen, —OH, —O-lower alkyl (in which the lower alkyl may be substituted with 1 to 3 OH, halogen, —O-lower alkyl (in which the lower alkyl may be substituted with one or more —COOH groups), or aryl groups), —CHO, —CO-lower alkyl (in which the lower alkyl may be substituted with 1 to 3 halogen atoms), —CO-cycloalkyl (in which cycloalkyl may be substituted with one or more —O-lower alkyl groups), —CO-aryl, a —CO-monocyclic saturated hetero ring group, cyano, —COOH, —COO-lower alkyl (in which the lower alkyl may be substituted with 1 to 3 halogen atoms), lower alkyl which may be substituted with —COOH or —O-lower alkyl, or lower alkenyl which may be substituted with —COOH or —O-lower alkyl, and s is 0, 1, 2, or 3.