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: 
Utterance: 'hi there 🙂'
Example Output: No

Example Input: Context: 'If I can have the 3 packs of food and 3 packs of water, then you can have 2 packs of firewood.' 'oh god. without food and water how can i survive in the camping trip?' 'This is true. Although we're negotiating for extra provisions.  I understand your situation, though.  I can use 1 pack of firewood, 2 pack of water and just 1 pack of food.'
Utterance: 'okay fine. now it is suitable for both of us'
Example Output: Yes

Example Input: Context: 'I would need firewood to cook my food as well. I would like the 3 water, 1 food, and 1 firewood, what about that? ' 'Since the value of water exceeds both food & firewood, I think it's fair for me to receive the extra dose of firewood. My offer to you is: you get 3 water, 1 food,  0 firewood.  I would get 0 water, 2 food, 3 firewood.' 'Okay you have a deal.'
Utterance: 'Great. I'll send it over '
Example Output:
No