Zoho CRM mass merge duplicate contacts.

Zoho CRM mass merge duplicate contacts.

I synced my Zoho CRM and Gmail contacts using a 3rd party software that I regret trusting. Basically I have duplicates of my almost 800 contacts. I'm going through each one and merging the contacts, but there honestly has to be a mass search for "similars" or duplicates. Both yahoo and gmail have features like this. I'm looking for exactly the same function that will show me to similars and allow me to choose which fields to keep from which duplicate. 

How can I do this?

Ryan