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:       When can we expect you and your daughter for dinner ? Next Saturday ?  
 Person2:Next Saturday ? I ’ m sorry . I ’ Ve promised to go to a Chinese Opera with my daughter .  
 Person1:        How about Sunday then ?  
 Person2:Yes , Sunday sounds fine . What time ?  
 Person1:        Does 6 thirty suit you ?  
 Person2:It suits us fine . We ’ ll see you then .  
 Person1:        Thanks , goodbye . 

informal