Andrius Arvydas and Lina Vilkas:)

I don't know. I feel like it Saoirse Ronan would do an excellent job as Lina because she is such an incredible actress, but as for Andrius, I can't really think of anyone.

There is a fantasy casting forum here:
http://www.iflist.com/stories/betweenshadesofgray#

I like Ondra Zelary for Andrius

I HAVE NEVER BEEN SO EXCITED ABOUT A BOOK TO FILM ADAPTATION!!! It got awkward even recommending the book to people because 50 Shades of Rubbish came out the next year and people thought it was to do with that series... I love the current listing for Lina - Jamie Blackley or George Mackay would be my dream castings for Andrius. (if you haven't encountered them, check out their work) Ben Schetzer was adorable in The Book Thief but had to lose a lot of weight for that film, so now back to normal doesn't quite look right, but I think he could be a potential too. Cillian Murphy is a lot older than my other suggestions but could also be great. AHHH I'M SO EXCITED HAVING SEEN THIS NOW!!! :D

also forgot about Tom Hughes, who I think would be excellent.