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: 'Ha, woah that's exotic! I'll need some firewood as well, but maybe not as much as you! I'm planning on going hiking a lot, and will need some extra water, as, again, ill be hiking a lot' 'I will offer 3 water to you! You will maybe need more food with that much exercise? How about 2 food? I really need that extra firewood. Remember that the Catskills probably has some extra wood around.' 'That works for me, you can have the firewood then!'
Utterance: 'Alright that sounds great. '
Example Output: No

Example Input: Context: 'Hello. How are you?'
Utterance: 'I am good. I am pretty excited for the trip this weekend. what about you?'
Example Output: No

Example Input: Context: 'Ya definitely. I need food and firewood most. What do you need?' 'I believe that we have the same priorities.  So we have a large family including children that need the food, but my wife also needs firewood due to poor circulation.  She is susceptible to frost bite and limb loss' 'Okay so how about one of us takes 2 of the food and 1 of the firewood, and the other takes 1 of the food and 2 of the firewood?'
Utterance: 'that sounds fair.  I will take 1 food, 2 firewood, and 2 water, thus giving you 2 food, 1 firewood, 1 water'
Example Output:
Yes