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:       Is this watch yours ?  
 Person2:No , it isn't mine . I blundered upon it under the sofa . Do you know whose watch it is ?  
 Person1:        Let me have a look . It's mine . I have been looking for it , but just cannot find it . It's present from my father .  
 Person2:Well , here you are . Remember to put it in a proper place . 

formal