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 ’ d better be going . 
 Person2:So soon . Why don ’ t you stay a little longer ? 
 Person1:        I wish I could , but It ’ s already late . 
 Person2:Oh . It ’ s pity you have to leave . 
 Person1:        thank you for wonderful meat . 
 Person2:I'm glad you enjoy it . 

informal