Uhm. Lithuanian army is same kind than finland ?
U must be there from 6 month up to 12 month? and back to reserve?
Oh i miss army times.. i was year there. and now am reserve sergeant.
Well actually first 3 month was shit.... but after it it was awesome. 
In Lithuania anyone can join army within age range 18-36. It's called 'Baziniai kariniai mokymai" (Basic army training or something like that)
Duration: 3 months
It's very hard there and so on, but I don't afraid of that.

When you finish it, you're put in reserve and you can join a proffesional army or a volunteer army.
Proffesional army is like a job where you get paid and etc.