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:       Are you working or are you a student ?  
 Person2:I'm a student .  
 Person1:        Which school are you studying at ?  
 Person2:Tsinghua University . 

formal