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: 'Awesome - same, I also need a ton of food. Will firewood be of interest to you as well? I'll be happy to compensate in this way' 'Firewood is not overly interesting to me, but water is somewhat enticing.' 'Ok, great - I can give you all of my waters in exchange for a majority of the food and half of firewood'
Utterance: 'Half of firewood? There are 3 so one of us has to get more. I would need more of that. '
Example Output: No

Example Input: Context: 'Great, we can split the food, how are you on water?' 'That would be great. I need to have frequent small meals throughout the day so the extra food would help. I have plenty of water. ' 'alright, so I'll keep the water, and firewood, and give you 2 extra food.  Does that sound like a good deal?'
Utterance: 'I actually need one firewood and one food package. I can give you one water. '
Example Output: No

Example Input: Context: 'Let's see what we are both thinking and negotiate from there. What are your first thoughts on the additional camping packages?' 'I need all the food packing and some basic needs for the camping, may I know about your first though on which you need additional package?' 'I will need food packaging as well, so unfortunately I cannot agree on you taking it all. I will need 2 of the food packages, 1 of the firewood, and 2 of the water as I want to ensure to feed/hydrate my family of 5.. Does this work for you?'
Utterance: 'I can't agree to this, as I have to feed my family with 7, so I would be needing 3 food packages and 2 water and 2 firewood. will this be agreed by you?'
Example Output:
No