If Stack is a template, then you have to provide it's template arguments when you reference it.
The error is possibly in your Stack class. The compiler has only tried to compile it now because it is being used.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.