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: 'No. That's not what I am saying. You can take all 3 firewood and I would like all 3 food.' 'aha, i basically just said that. I was asking about the water. I said I would get all 3 firewood and all 3 water and you would get all the food (3)' 'How about I take 2 water and you take 1 water?'
Utterance: 'I don't really think that's fair given you're taking all the food. I would be willing to do the following: 2 firewood, 0 food, 2 water'
Example Output: Yes

Example Input: Context: 
Utterance: 'hi, I'm looking forward to going camping soon'
Example Output: No

Example Input: Context: 'Could you trade one food item for either one firewood or water?' 'How about this- You will get 1 food, 1 water and 3 Firewood. I will get 2 Food and 2 Water with 0 Firewood. ' 'Hmm, I think I would prefer your original offer instead.  You can have all the food if I can have all the rest.'
Utterance: 'Hmmm i don't beleive i ever offered you everything for all the food. I will need at least one water. lets not be selfish.'
Example Output:
Yes