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:       How old are you ?  
 Person2:Nine ... but I'll be ten on May 1st.When is your birthday ?  
 Person1:        I'm older than you ! I'll be ten on April 14th .  
 Person2:Are you going to have a birthday party ?  
 Person1:        Maybe . I'll have to ask my mother . 

formal