I had locally setup the odoo project on my machine. I am working on a issue where I have to merge the duplicate contacts in an automated manner. But before I wanted to create few duplicate contacts on my own. While adding the mobile number to the contacts the autocomplete feature fills the number with a "-" sign which generates the error on my backend. The validation logic for mobile number on my backend is only 10 digits.
I have attached the screenshot of autocomplete feature on contacts. 
When I try to save this it shows the invalid number error.
Also, I am new to odoo so what further steps should I take to automatically merge the duplicated contacts in odoo. I found out about adding the deduplication rules in odoo to merge the duplicated contacts but I could not find the proper implementation of this solution. And is there any other approach to do this?
