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 ’ m really glad I got a chance to talk to you before you left , Mary . Have a safe trip !  
 Person2:Thanks . Try not to work too hard while I ’ m away !  
 Person1:        Yeah , I ’ ll try not to ! See you after Christmas .  
 Person2:Okay-bye ! Have a nice Christmas . 

informal