You will be given a definition of a task first, then some input of the task.
The input is taken from a negotiation between two participants who take the role of campsite neighbors and negotiate for Food, Water, and Firewood packages, based on their individual preferences and requirements. Given an utterance and recent dialogue context containing past 3 utterances (wherever available), output Yes if the utterance contains the vouch-fair strategy, otherwise output No. vouch-fair is a selfish negotiation strategy. It is used to call out fairness for personal benefit, either when acknowledging a fair deal or when the opponent offers a deal that benefits them. This can be through an explicit call out or can be implied.

Context: 'Hmm I think I should take 2 food, 1 firewood, and 3 water. What do you think?' 'Is your first priority the water?  I'm definitely willing to split up by what is most important to us both.' 'Food is actually my first priority but since it seems to be first priority for us both I thought we could split that. Water doesn't seem to be a priority for you so thought I could take that'
Utterance: 'My first priority is actually firewood.  Food is my second.  🙂'
Output:
No