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:       I'm sorry I'm late . 
 Person2:Oh , that's all right . I just wondered what was keeping you . 
 Person1:        The bus I took . 
 Person2:What do you mean ? 
 Person1:        I took the wrong bus . 
 Person2:Oh , did you ? That's very easy to do . 

formal