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:       Well , my particular interest is collecting stamps , especially the rare ones . What about you ? 
 Person2:I ’ m afraid that ’ s not my cup of tea . I just find skin-diving attracting . 
 Person1:        So have you ever been to the stamp display of the town ? 

informal