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: 'well I am sure between you and me we will find a way....' 'I really need some food, but I could also use extra firewood. It is supposed to be pretty cold at night and we would love to cook up some smores.' 'I hear you we have the same issues well you can have either 2 food or 2 firewood what would you prefer?'
Utterance: 'I would prefer 2 food. I could give you 1 food, 2 firewood and 2 water?'
Example Output: No

Example Input: Context: 'Hi, ' 'Hello. What sort of supplies are you looking for?' 'Well, I really dislike camping  :( and am looking to make the trip as comforting as possible.  I would like to gather 2 food, 2 firewood and 2 water please.  '
Utterance: 'I need a lot of food and I get cold easily. What is your top priority?'
Example Output: No

Example Input: Context: 'So I get 2 waters/2 food/0 firewood, and you get 1 water/1 food/3 firewood? I think that works for me.' 'Yes, that's the plan. By the way, what do you need all that food for? You didn't say. I'm just curious.' 'I'm a bigger guy (6'3") so I eat a lot, especially after activities like hiking and kayaking. Same reason I want water really.'
Utterance: 'OK, that makes sense. I don't eat as much as you do, so it's only fair that you get most of the food. So I hope this deal will be fair for both of us and you'll walk away happy.'
Example Output:
Yes