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:       Watch out ! You'll hit that car if you're not careful .  
 Person2:Oh no , I won't . But we will have an accident if you don't stop shouting .  
 Person1:        You see . I told you you'd hit him if you weren't careful .  
 Person2:Oh , shut up , will you ? It was all your fault.If you'd kept quite this would never have happened .  
 Person1:        Oh , so it was my fault , was it ? If I hadn't warned you in time it would have been much worse . 

informal