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:       Hello , let me introduce myself . I'm your new neighbor . My name is Andy .  
 Person2:Hi , Andy . I'm Judy . It's nice meeting you .  
 Person1:        Nice meeting you , too .  
 Person2:Come over and visit when you have time .  
 Person1:        Thanks for the invitation . I will ! 

informal