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:       Mom , Happy mother's Day ! Here's my card .  
 Person2:What a surprise ! Thanks.It ' s beautiful .  
 Person1:        Thank you for your love and care over the years , I appreciate it , mom .  
 Person2:This is the best card I ever received .  
 Person1:        Mom , what can I do for you today ?  
 Person2:Nothing , son . I'm already very happy .  
 Person1:        How about dinner tonight ? My treat .  
 Person2:Actually . I prefer we eat at home.We ' ll have more time to catch up that way .  
 Person1:        I'm sorry I haven't dropped in that much these past few years.Business kept me too busy , I apologize .  
 Person2:Oh , don't mention it . I'm proud of you !  
 Person1:        Thank you , mom . I love you so much ! 

informal