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: 'My biggest concern is water.  I could really use more.  That and some extra food.' 'My biggest concern is food and then water. ' 'I'm going to need quite a bit more water, at least 2 packages.  I would like at least 1 food. What do you think?'
Utterance: 'How about you take two water and 1 food and 2 firewood?'

No