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:       Do you like swimming ?  
 Person2:Yes . Swimming is one of my most favorite sports , indoors or out-doors .  
 Person1:        Me too . Swimming is a very good exercise for health . It combines water , bath , sunbath , and air bath together . It promotes the growth and haleness of muscles , bone , viscera and nerve systems .  
 Person2:I have never thought that swimming can bring us so many benefits . I only know that swimming in great waves and deep running water can train people's spirits , and enable people to be fearless of the hardships , dangers and difficulties and become brave and staunch .  
 Person1:        Have you ever swum in a river or a lake ?  
 Person2:Yes , but not always . However , I won't let it go if I have a chance . 

informal