As Graynomad mentioned, this is the biggest hurdle in converting requirements into code. Requirements can be of varying levels of ambiguity. There is zero ambiguity in code.
In this case, the phrase 'into the forest' needs to be more specifically defined. Without that definition, any answer is just an interpretation that may or may not be correct. It could be half way, it could be all the way. It could be something else entirely if 'into the forest' has some non-intuitive meaning. For example, it could just as easily mean a single step if 'into the forest' is simply a binary state.