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: 'No I cant give you all the firewood. I will take atleast one firewood. Also can I have all three water bottles. ' 'the absolute most water I can spare is 2 and , my firewood is pretty much useless. I can give you 2 water and 1 food for 2 of your firewood that is my final offer' 'Ok. I will have 2 water, 2 firewood and 1 food. Am I correct?'
Utterance: 'no, I can give you 2 water and one food if you give me 2 firewood'
Example Output: Yes

Example Input: Context: 'I have a medical condition that causes my veins to close up when I get too cold. I will thus need the 3 firewood.' '☹️Oh, that sounds awful. Are you sure you need all three packages of firewood?'
Utterance: 'I might be able to get by with just two... I'm on a diet though, so I don't need as much food.'
Example Output: No

Example Input: Context: 'How many food would you like to trade for water?' 'How about 2 Water for 3 food?' 'That sounds like a good deal but I could use some firewood as well. Would you throw one of those in as well?'
Utterance: 'That doesn't seem very fair ☹️. That would be 3 food and 1 firewood for 2 water. That is 4 items exchange for 2.'
Example Output:
Yes