Getting the remaining child number of a passage.

Hi,

Is there any way, using Ink, to know the number of possible remaining passages of a story?

Let say my story looks like this with A being the first passage of the story :

> A-->B-->END
> |-->C-->F-->G-->H-->END
> |-->D-->E-/

On A I'd like to know that a maximum of 4 passages (C->F->G-H) and a minimum of 1 passage (B) remain.
On F the min and max remaining value would be 2 (G->H).
On B the min and max remaining value would be 0 (B has no child).

Is there any built-in feature in Ink that can do something like that. If no, can you please tell me where I should look at in the code to start working on such a feature?

Thanks.