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: 
Utterance: 'I'd like to have 2 extra packages of water and firewood.'
No

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!🙂'
No

Context: 'I am just going to walk away,  I can't have my family freeze' 'I do not want my family to freeze either but walking away doesn't benefit either of us. How about I take the water and 2 firewoods, you have the rest' 'No deal, I need at least 2 firewood'
Utterance: 'Ok, I can agree to 2 firewood but I will have to take all the food and water to compensate'

Yes