Get the list of users from an Github Org who are not part of any team

I am looking for an api (or a combination of apis) to get the list of users from an Github org who are not part of any teams. I explored few REST apis and it doesn’t look to be a straight forward one. I need to get the list of users, then list of teams and iterate users to check their membership with each teams. It is tedious. Any other suggestion to achieve this?