Disclosed are compounds of Formula (I): or a salt thereof, wherein: Z is CR6R6 or C═O; Ring A is: and R1, R2, R3, R4, R5, m, and n are defined herein. Also disclosed are methods of using such compounds to inhibit Helios protein, and pharmaceutical compositions comprising such compounds. These compounds are useful in the treatment of viral infections and proliferative disorders, such as cancer.