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:       I would like to make a reservation for tomorrow .  
 Person2:I'm sorry but we are fully booked .  
 Person1:        Well , how about 4th ?  
 Person2:That's fine , but we have only a single room , is that OK ?  
 Person1:        Yes . Please help me reserve it . 

formal