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:       Oh , you can rest assured that they'll be no problem .  
 Person2:Why is that ?  
 Person1:        Your upstairs neighbors live in Canada and rarely come back to Taiwan . When they do , they're never home .  
 Person2:And the downstairs neighbors ?  
 Person1:        Two flight attendants that are also in and out of town . When they're here , they're usually sleeping . And next door to you is me . I'm a quiet neighbor .  
 Person2:Sounds ideal . We'll get back to you in a couple of days then . 

informal