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 wish I could unsay the sharp words to him . He must hate me very much . 
 Person2:He doesn't mind . As a matter of fact , he's very pleased . 
 Person1:        Really ? Oh , thank Goodness ! 

informal