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 elicit-pref strategy, otherwise output No. elicit-pref is a cooperative negotiation strategy. It is used to discover the preference order of the opponent in the negotiation.

Context: 'I really appreciate that. Do you think you will be okay with just 1 water since you have health issues?' 'That would be very nice, but I worry about you not having enough on the trail.  Dehydration would not be good.  I am pretty sure I can ration my supply to make it last.  🙂' 'You're a good friend! I'm excited to embark on this adventure! 🙂🙂🙂'
Utterance: 'Me too!  So let me clarify:  I will take 2 firewood, 1 water and 1 food.  You will take 1 Firewood, 2 water and 2 food.  Is that right.  🙂🙂🙂'
No

Context: 'It will be nice to get out and explore the great outdoors, even if it is super hot!' 'I agree. What supplies could you use more of?' 'Water for sure, need to stay extra hydrated.  How about you?'
Utterance: 'Haha yup I had a feeling about that one. ;-) Yeah my wife has a bunch of crazy hikes planned so water is a must here too. What else?'
Yes

Context: 
Utterance: 'Hi there.. we're looking forward to this camping trip.. hope you are, too!  Is there anything in particular you guys need / want out of the extra stockpile we've got?'

Yes