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:       Welcome aboard .  
 Person2:Excuse me , Miss . Can you show me my seat ?  
 Person1:        Let me have a look at your boarding pass . It's E - 6 , the sixth seat by the aisle .  
 Person2:Thanks a lot . 

informal