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.
One example: Context: 'Yeah, I'm going to the desert so I'm hoping to have enough water. I'm good on food and I hunt for a lot of it anyways.' 'I've never been a good hunter. I wish I had those abilities.' 'I would part with all the food if I could get all the firewood.'
Utterance: 'That seems fair. How about water. How would that be split? I'm very concerned.'
Solution is here: Yes
Explanation: This is correct since the participant points out that the proposed deal seems fair.

Now, solve this: Context: 'You would get 2 water and 2 food, I would get 1 water and 1 food for hiking and 3 firewood for having to stay out longer in the dark to complete my hiking goals.' 'doesn't really seem fair for you to get all the firewood. I would like to have at least one because then we're completely in the dark.' 'You get lots of water and food for your children, I am cutting back on my goals by giving up energy which means I have spend more time outside hiking.  I do need to stay warm'
Utterance: 'yes which is why you have two firewood. I think it is fair for me to get at least one. If food is so important to you then I'll give you two food. but we would be in the dark'
Solution:
Yes