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:       Sir , here is your curried beef . 
 Person2:Well . I am afraid you have made a mistake . It's not the dish I ordered . 
 Person1:        Let me see , I am sorry . It's for table 11 . 
 Person2:It doesn't matter . 

informal