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:       Here's your drink , sir . 
 Person2:No , that's not right . I didn't order a coffee . I ordered a cola . 
 Person1:        Oh , I'm terribly sorry , sir . I'll go and get you cola right away . 
 Person2:Waiter ! 
 Person1:        Yes , sir . I'll bring your drink right away . 
 Person2:It's not that . There's an animal in my soup . 
 Person1:        Is there , sir ? I'm very sorry . I'll change it straight away . 
 Person2:I've never been to such a dirty restaurant , and never seen such slow service . 
 Person1:        I'm really sorry . 

informal