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:       Here is my ticket and seat assignment . 
 Person2:Thank you . That way , PLS . 
 Person1:        May I have a pillow and blanket , PLS ? 
 Person2:An attendant will pass them around after we take off . 
 Person1:        May I have headphones for the in-flight movie ? 
 Person2:No problem . Here are your headphones . Do you want something to drink ? 
 Person1:        Thanks , a coke , PLS . 

formal