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:       Man , that sunset is beautiful . I ’ Ve never seen one so red .  
 Person2:Yeah , it ’ s pretty nice , but its so red because of air pollution .  
 Person1:        Really ?  
 Person2:Yeah , the smog from all these cars gets into the air and turns the sunlight red .  
 Person1:        I never knew that .  
 Person2:Yeah , more people need to take public transportation or carpool .  
 Person1:        Well , we ’ Ve already done our part .  
 Person2:Yeah , it ’ s your turn to drive next week . Don ’ t be late picking me up .  
 Person1:        Don ’ t worry . I ’ m getting more sleep these days . The baby ’ s finally growing up a little more .  
 Person2:Well , give me a call if you can ’ t make it for some reason . 

informal