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:       The car isn't running smoothly . I'd like to have a look at it . 
 Person2:What's the matter with it ? 
 Person1:        I'm not sure . It could be the tires . Let's stop here . 
 Person2:How about the tires ? 
 Person1:        Nothing serious . The right one needs some air . 

formal