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:       I'm calling to cancel a reservation I made earlier in the week .  
 Person2:To cancel your reservation , I need your name , phone number , and date of trip , please .  
 Person1:        Rudy Randolph , 818-555-1234 . My reservation begins on the second Monday of April .  
 Person2:I see your reservation on my computer . Let me just cancel it , and you'll be all set !  
 Person1:        Thanks . I'll call again when things get better at home .  
 Person2:You're welcome . 

informal