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:       Forest Restaurant . What can I do for you ? 
 Person2:May I make a reservation ? 
 Person1:        Of course . At what time ? 
 Person2:The four of us will be there at 7:00 this evening . 
 Person1:        OK , sir . We are looking forward to your arrival . 

informal