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: 'Okay, but water is important to me because I have health issues. So I drink more water for save my health.' 'Okay! You can have all the water. I want all the food.' 'yeah sure, I will share with you all the food. What is about firewood?'
Utterance: 'You can have two if I can have one if you're okay with that.'
Example Output: Yes

Example Input: Context: 'i botttle of water for a can of food and 2 firewoods' 'Yeah, sorry, that's not going to work out for me.  I'm going to need at least 2 bottles of water, 1 food packet, and one firewood.. again, this does leave you with two each on the food and the firewood, which are both very important things for this camping trip!' 'but thats the only offer im willing to give'
Utterance: 'Well then unfortunately I think we're gonna have to walk away from this and neither of us gets anything we could both use.. that's unfortunate and I'm sorry to see it end in such a less than magnanimous fashion ☹️'
Example Output: Yes

Example Input: Context: 'Hi' 'Hi! 🙂' 'So what are you thinking about how we should split this? i really want firewood, as i am anemic and have a hard time in the cold weather during the nights here'
Utterance: 'Well, I need to keep some firewood for myself too, since it'd be cold outside. But I'm willing to trade more of it for food, since I'm iron-defcient and have family to feed!🙂'
Example Output:
No