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: 'I really don't want to be without water, how about 2 water and 2 firewood for the 3 packages of food?' 'I just want to make sure I understand you I get 2 waters and 2 firewood and 0 food. ' 'That's right. Since you would be getting food from your sister, while I am camping alone, you would be getting more food pretty soon. '
Utterance: 'umm. I think the best and fair deal is a complete swap of water for food and you get 2 fire wood. '
Example Output: Yes

Example Input: Context: 'Camping yay!' 'Hello! how are you? hoping today is finding you well. I was wondering if I can get all 3 of your Firewood, I am willing to trade for all 3 waters. I am camping with 40 kids, its our annual youth camp. its rainy season too, I really want to ensure I have enough dried wood with us. need lots of firewood for the amount of cooking I will be doing, keep the camp warm, and specially to keep those pesky bugs away. what do you think?'
Utterance: 'I could really use the firewood too, it will be very cold where we are going. Since it will be cold, we will not be drinking much water. How about 2 firewood for you, 3 food for me?, '
Example Output: No

Example Input: Context: 'Hi' 'Hi how are you' 'I'm doing great. How about you.?'
Utterance: 'Really good.'
Example Output:
No