Detailed Instructions: You will be given a context and a verb separated with a newline character, and you have to answer if the given verb is a negation or not. A verb is a negation if it is not going to exist, not happen, or has no effect. The output should be "Yes" if the verb is a negation and "No" otherwise.
See one example below:
Problem: Only the government of the United States can decide if it prefers this variant, continued the letter, which Castro read on a state television station broadcast. Gonzalez for months refused requests by Elian's Miami relatives to go to the United States to (claim) the boy.  
 Verb: claim
Solution: Yes
Explanation: This is a good example. Gonzalez refused to "claim" the boy. So, the claim didn't happen and it's a negation.

Problem: It was unclear if American authorities would give the Cubans the 28 visas they have proposed. The group would not (leave) until Gonzalez had assurances that American authorities would give him custody of his son.  
 Verb: leave
Solution:
Yes