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:       Wei , you look really tired .  
 Person2:Yes , I didn ’ t finish work until 9:00 pm .  
 Person1:        9:00 !  
 Person2:Yes , I have too much work to do at the moment .  
 Person1:        Why ’ s that ?  
 Person2:Because too many people in the office are on holiday . 

informal