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:       Hi , do you know what ’ s for dinner ? I ’ m starving .  
 Person2:We ’ re on our own tonight , dad ’ s taking mom out .  
 Person1:        Out ? What do you mean out ?  
 Person2:You know on a date , they are going to dinner .  
 Person1:        Dad and mom ?  
 Person2:Yeah , they said they ’ re reviving the old tradition .  
 Person1:        You mean this is going to be a regular thing ?  
 Person2:That ’ s right , once a week . Do you want to order some pizza ? 

formal