For those like me failing to properly configure ANAME records for Heroku here are some ip addresses digged from Heroku docs that can be used to configure CNAME:

@ A 174.129.212.2 @ A 75.101.145.87 @ A 75.101.163.44 www CNAME yourapp.herokuapp.com.

Sure, it’s a bad practice and should be used only in despair.