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:       Good morning , Miss Li .  
 Person2:Morning , Mike .  
 Person1:        I ’ m sorry that I was absent yesterday .  
 Person2:I ’ Ve already got your certificate for sick-leave . How do you feel today ?  
 Person1:        I feel much better now .  
 Person2:Have you received the reading material handed out yesterday ?  
 Person1:        I ’ Ve already got it . Thanks .  
 Person2:I will explain it in detail in the next class . Could you preview it ?  
 Person1:        I will . 

formal