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:       How large is the plant ?  
 Person2:It covers an area of 75,000 square meters .  
 Person1:        It ’ s much larger than I expected . When was the plant set up ?  
 Person2:In the early 70s . We ’ ll soon be celebrating the 30th anniversary .  
 Person1:        Congratulations !  
 Person2:Thank you .  
 Person1:        How many employees do you have in this plant ?  
 Person2:500 . We ’ re running on three shifts .  
 Person1:        Does the plant work with everything from the raw material to the finished product ?  
 Person2:Our associates specializing in these fields make some access - ries . Well , here we ’ re at the production shop . Shall we start with the assembly line ?  
 Person1:        That ’ s fine . 

formal