List of user logon date/times in Active Directory

Do you guys know of a good tool that will show the last logon time of user accounts in AD in a list? I want to do this so I know which accounts have not been used for an extended period of time so I can delete them. I did a google search and found a few tools but they were all demo/trial software and I hoped to find something free. If there is nothing free out there that can do this any other recommendations would be appreciated.
Working on: MCSA 2012 R2
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