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". 

[EX Q]: Event:PersonX prevents ___ from obtaining. Intent:
[EX A]: Negative

[EX Q]: Event:PersonX eventually bought ___. Intent: 1) angry at students 2) frustrated 3) trying to get students' attention
[EX A]: Positive

[EX Q]: Event:PersonX feels PersonY's presence. Intent: 1) to go swimming 2) cool down
[EX A]:
Unknown