A compound having antiviral activity, specifically a heterocyclic compound having HIV integrase inhibitory activity; and a medicine containing the compound, especially an anti-HIV drug. The compound is a compound represented by the formula (I): (I) [wherein B is -C(R )= or -N=; R ' is hydrogen, etc.; one of R and R is a group represented by the formula -Z -Z -Z -R (wherein Z and Z each independently is a single bond, optionally substituted alkylene, etc.; Z is a single bond, optionally substituted alkylene, etc.; and R is optionally substituted aryl, optionally substituted heteroaryl, etc.) and the other is hydrogen; and -A - is -C(-Y)=C(-R )-C(-R )=C(-R )- (wherein Y is -OH, etc.; R is -COR (R is hydroxy, etc.), etc.; and one of R and R is carboxy, etc. and the other is hydrogen, etc.), etc.], a prodrug of the compound, a pharmaceutically acceptable salt of either, or a solvate of any of these.