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:       Driving during the rush hours can be a bit of a bind .  
 Person2:Yeah . I think so.You have to be patient and careful .  
 Person1:        So I'd rather walk or run to work .  
 Person2:You must be joking ! 

informal