Definition: 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.
Input: Context: 'Of course. So, what about food? I will definitely need the food. I have a big family, and we all need to eat. I can't have people starving. Can I take all of the food?' 'Okay I accept that.' 'Wonderful. And what about the firewood? I would like 2 firewood, and I can give you 1 firewood. Will you accept that?'
Utterance: 'Okay I accept your deal.'

No