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:       Brandy , I am supposed to participate in an interview tomorrow .  
 Person2:That's great . You need to prepare for it .  
 Person1:        How ?  
 Person2:Buy an expensive suit .  
 Person1:        Is a white shirt OK ?  
 Person2:Yeah , fine . And dressing leather shoes . 

formal