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.

Example Input: Context: 
Utterance: 'Hello! camper, how are you? I need us to make a deal where we all benefit.I'm so excited for our camping trip.  I'm most excited about getting to eat food that I normally don't when I am home.🙂'
Example Output: Yes

Example Input: Context: 'I totally understand! I am in need of food too, but it sounds like you really need it so I am hapy to give you all of the food if I can have all of the firewood?' 'What is your need for water?  I could use some of that, too.' 'I am pretty desperate for water! I tend to get thrisy when camping. Can I have 2 of the water?'
Utterance: 'I could live with that but I'd need to get one firewood.  I don't feel comfortable going with so little water but then also not having any firewood, since that's potentially useful for both food and water.'
Example Output: Yes

Example Input: Context: 'I don't need the water as much.  How about I get 2 firewood and you get 2 water?' 'I would prefer all the water. You can have all of the firewood.' 'That sounds good to me.  What about the food?'
Utterance: 'I would like 2 food, but you may have one. I wouldn't want you to be too hungry!'
Example Output:
Yes