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 must be going now .  
 Person2:Really ? Can ’ t you stay a little longer ?  
 Person1:        No , I really must go now . My family are expecting me home soon .  
 Person2:Be seeing you then .  
 Person1:        See you . 

informal