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 am exhausted . I need some sleep . 
 Person2:Didn ’ t you sleep well last night ? 
 Person1:        I twisted and turned all night , and couldn ’ t sleep . I was worried about my mother ’ s health . 
 Person2:Don ’ t worry . It ’ s only a cold . 

formal