Given the task definition and input, reply with output. 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'.

Person1: Excuse me . Could you please take a picture of us with this camera ?
Person2:Sure . Which button do I press to shoot ?
Person1: This one .
Person2:Do I have to focus it ?
Person1: No , this is a focus-free camera . All you have to do is point and press the button .
Person2:All right . Say cheese !
informal