Solutions that depend on the hidden number being non-zero pass. Consider if you want this. If you do, the description should probably specify the number will be positive. If you don't, there should probably be a test with a hidden 0. ( Negative numbers are also a possibility, but are less likely to trip up solutions. )

Name is currently extremely non-descriptive, something indicating it's a tree based task would likely fit better.

Description examples seem a tad non-obvious/hard to parse for us as currently formatted.

Might be worth showing them prettyprinted with line breaks/indents with annotations in comments.