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:       Would you mind helping us take a picture ?  
 Person2:My pleasure . How do you want me to do it ?  
 Person1:        Just focus on us and press the button .  
 Person2:Ready ? Say cheese . 

formal