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:       Hello , Friendship Restaurant . May I help you ?  
 Person2:I'd like to book a table tonight .  
 Person1:        Yes , Sir . For how many people , please ?  
 Person2:Eight .  
 Person1:        What time ?  
 Person2:Eight o'clock tonight , would you please set us in a private room ?  
 Person1:        So sorry , we're fully booked in that room . Would you like to make reservation some other time ?  
 Person2:Maybe not , thank you all the same then . 

informal