INTERRAIL: DO I HAVE TO START IN MY COUNTRY OF RESIDEN

Is there an obligation to take the train to get out of our country ?
Do I have to start in my country of residence ?
I'm French and I would like to start my trip in Greece, so is there a problem if I first take a plane to reach Greece, and then start using my Interrail ticket in Greece ?
Thanks for your answer !

You are okay to fly out of your country, that's how I started my trip. In fact, it's probably the best way to do it!
Have a great trip!