Report that shows accounts with no activity

Report that shows accounts with no activity

I need help creating a report that allows me to quickly see which accounts have had no activity. I've been researching and it looks like the only solution is to use last activity time. However, that records any time an action is taken on the account, incuding when the record is updated with a sales order (via API). What I really need to see is by sales person, all of his/her accounts that he/she has recorded no open or closed activities in the past 90 days. Is this possible?