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:       It looks delicious . I will order it .  
 Person2:I am sorry , sir , it's for 4 persons to have . I think it's too large for you .  
 Person1:        Would you please make it for a single person ?  
 Person2:Sorry , sir . We have never done that before . 

informal