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:       What ’ s the matter , Sally ? You look so unhappy . 
 Person2:I had a bad day yesterday . 
 Person1:        What happened ? 
 Person2:I went to the library and lost my bag . 
 Person1:        Your bag ? Did you get it back ? 
 Person2:I went back for it . But it was already gone . 
 Person1:        That ’ s too bad . I ’ m sorry to hear that . 

informal