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: 'Unfortunately it is impossible as we are already on site compared to you about to head out. ' 'I see. You are a victim of poor planning. Whereas the refugees I attend to are the victims of greed, malice and human suffering. What are you proposing?' 'How about I take 2 packs of water, 2 packs of food and 1 firewood'
Utterance: 'Impossible. I will need to cancel the trip altogether.'

Yes