How many apples?

My daughter nearly every day is asking me to play with her and to solve small problems.
But not all problems are easy for her.
For example such one we could not cope with:
You have an apple. You throw it up to the apple-tree and two apples fall from there but yours one is held up there. How many apples you have now?
Now you take again an apple and again throw up. Other two apples fall, but yours again sticks somewhere.
Now, how many apples you have?