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:       Do you live with your parents ?  
 Person2:No , they live in Shanghai , my hometown .  
 Person1:        How often do you go back to visit them ?  
 Person2:Once a year . 

formal