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: 'how much firewood do you need' 'I would like 2' 'I will  be happy to let you have 3 packs of food , but I need 2 packs of firewood'
Utterance: 'I am also letting you have all 3 packs of water. I think we need to consider how to split the firewood in a fair manner.'
Example Output: Yes

Example Input: Context: 'How about I take 2 packs of water while retain your initial request for food and firewood?' 'I cannot allow any water. As I mentioned we will be camping away from all bodies of water and cannot negotiate on that item. I need 3 water, or else I will need to cancel the trip. We might be able to negotiate on the food though.' 'I need to have at least a pack of water. How about 1 water, 3 firewood and 1 food?'
Utterance: 'Okay. I fear some of us may die of thirst, but I will give you 1 water. I can't agree to those terms though. I can give you 1 water 1 firewood and 2 food. That is my final offer though.'
Example Output: Yes

Example Input: Context: 'That sounds awesome - I'm sure we can come to an agreement on how to allocate that works for both of us.  ' 'I agree that we will! I do love having food as well. Have lots of people coming.' 'I'm not as keen on food, so how does this sound.  I get 2 firewood, 2 waters, and 1 food.  You will get 2 food, 1 firewood, and 1 water. '
Utterance: 'Hmm, you're getting my top item there though. That still might work.'
Example Output:
Yes