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:       So , Karen , what do you do in your free time ?  
 Person2:Well , I like to play the piano .  
 Person1:        Really ? How long have you been playing piano ?  
 Person2:About 18 years , I started learning when I was a kid .  
 Person1:        That ’ s really interesting , you have to play for me some time .  
 Person2:Sure , so , what about you ? Do you have any hobbies ?  
 Person1:        Well , I collect beer mats . I ’ m not sure that counts , though . 

informal