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: 'so I'll get 2 water, 3 food and 0 firewood?' 'Incorrect. ' 'In order to make it work I need at least 3 water and 2 food. Or I could do 3 firewood and 2 food and 0 water. I don't see any other way around it'
Utterance: 'It has to be fair. Right now I don't think you are being fair. The last offer I gave was great for you. You all all of the food and 2 water.You wanted 3 food in your last offer so thats a great offer I suggested.'
Example Output: Yes

Example Input: Context: 'I would like 2' 'I will  be happy to let you have 3 packs of food , but I need 2 packs of firewood' 'I am also letting you have all 3 packs of water. I think we need to consider how to split the firewood in a fair manner.'
Utterance: 'What do you think is  a fair deal with the firewood'
Example Output: Yes

Example Input: Context: 'that will work for me - how about i take 2 food, and all the firewood - i am hoping to teach my boys campfire songs - they need other hobbies that dont include electronics :). You can have 1 food and all the water? ' 'I would like just 1 firewood so we can have a smores night with the younger kids if that works?' 'that works for me - would you be willing to give me 1 of the waters that way i at least have a little extra'
Utterance: 'No i really need all the water, if its a deal breaker than you can have all the firewood.'
Example Output:
No