Galaxy NOTE 4 N910F repairing IMEI …

Hi there
I have an N910F i wrote a cert file on it, before of that the IMEI was (empty) ( /01)
now every thing is okey but it’s illegal in my country to use a phone with a different IMEI because … well long story
My question : is there anyway to recover my original IMEI ?
P.S i don’t own any kind of backups
thank you in advance guys