You will be given a sentence. Check whether the sentence is grammatically correct and is meaningful. If the sentence is grammatically correct, then answer with '1', otherwise answer with '0'.

[EX Q]: Who did Athena introduce who to?
[EX A]: 0

[EX Q]: Joan knew the answer.
[EX A]: 1

[EX Q]: John thinks what Mary bought.
[EX A]:
0