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:       What do you think is the role teacher should play in the classroom ? 
 Person2:Teachers are just directors who give scope to the students ' initiative and creativeness , instead of taking their rights away from speaking . 
 Person1:        What did you do to put it into practice ? 
 Person2:I divided students into groups and asked them to generate their own ideas actively . It can help develop the problem-solving ability of the students . 

formal