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:       If ever you ’ re in Chicago , please do look me up .  
 Person2:Well , yes , I ’ d like to , if it ’ s not too much trouble .  
 Person1:        No trouble at all . I think maybe you will meet some of my friends here as well .  
 Person2:That ’ d be fine . 

informal