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:       Excuse me , can you suggest a good book for me to read ? 
 Person2:Yes , they are all on the shelf . 
 Person1:        Do you have an English-Chinese dictionary ? 
 Person2:Yes . Here you are . 

formal