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 , Shogun Restaurant .  
 Person2:Hi , I would like to make a dinner reservation .  
 Person1:        Of course , what evening will you be joining us on ?  
 Person2:We will need the reservation for Tuesday night .  
 Person1:        What time would you like the reservation for ?  
 Person2:We would prefer 7  
 Person1:        For how many people  
 Person2:There will be 4 of us .  
 Person1:        Fine , I can seat you at 7  
 Person2:Thank you . The last name is Foster .  
 Person1:        See you at 7  
 Person2:Thank you so much . I appreciate your help . 

informal