Definition: You are given a conversation between two people. 'Person1:' and 'Person2:' are used to separate their respective dialogues. You are required to assign a label 'formal' if there is an absence of emotion and a presence of questions anywhere within the conversation. If such pattern is not found assign the label 'informal'.
Input:  Person1:       What ’ s up ? You don ’ t look too good .  
 Person2:Yeah , my head hurts , that ’ s all . I ’ Ve been in physics class all day . It ’ s killer !  
 Person1:        I liked physics . It ’ s all math , really . arcs , curves , velocity , cool stuff .  
 Person2:Yeah , yeah , but today ’ s lesson was all about the creation of the universe .  
 Person1:        A physics class about the creation of the universe ? That ’ s some pretty unscientific language there . Sounds more religious to me .  
 Person2:It ’ s all religion . Take the theory of the Big Bang.How is it possible that all of the stuff in the universe comes from an explosion ? That ’ s no better than Atlas carrying the globe on his back or African myths about turtles and stuff .  
 Person1:        Turtles ? Whatever ... Look , all that ’ s required for the creation of matter an imbalance of particles and anti-particles . At least , that ’ s what the math says .  
 Person2:Math , sheath . What ’ s the evidence ?  
 Person1:        There is evidence ! You know Edwin Hubble ? He ’ s the guy who in the early twentieth century was the first scientist to measure the drift of matter in the universe , thus advancing notions of an expanding universe . What would it be expanding from ? Well , the Big Bang ... DUH !  
 Person2:Anyway , it ’ s just a theory . Why do people go around touting theories ? Where ’ s the scientific rigor in that ?  
 Person1:        Dude , don ’ t equivocate . A theory only becomes a theory after withstanding rigorous testing . You slept through class , didn ’ t you ? 

informal