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:       Happy Mother's Day , Mom !  
 Person2:Thanks ! These are beautiful . You shouldn't have !  
 Person1:        Of course I should have ! You certainly deserve them ! You put up with all of us .  
 Person2:I forgot what I put up with . In that case , I do deserve these flowers . 

informal