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:       Have you been to Shanghai before ?  
 Person2:Yes I have . I ’ Ve been there three times in the past year .  
 Person1:        That sounds great . Have you been to the top of the Pearl Tower ?  
 Person2:No I haven ’ t . I haven ’ t visited the Bund either . I ’ Ve always had too much work to do .  
 Person1:        So you haven ’ t done much then , in Shanghai ?  
 Person2:Actually , I ’ Ve eaten soup dumplings in a lovely restaurant on Nanjing Lu . They were delicious ! 

informal