You are provided with an "Event" and it's "Intent" related to PersonX. Determine the sentiment value of the given input as either "Positive", "Negative", and "Unknown". 

Event:PersonX never thought. Intent:
Unknown

Event:PersonX loses PersonX's identity. Intent: 1) to serve his country
Unknown

Event:PersonX expresses PersonY's ___ in terms. Intent: 1) to be appreciative

Positive