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:       I hear little Bob has recovered .  
 Person2:That's a great relief . I was worried about him .  
 Person1:        The operation was very successful .  
 Person2:His parents must feel very happy . 

informal