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: The weekend's finally here !
Person2:And it's a long one . I have Monday off . It's Memorial Day or something like that .
Person1: Yep . It's the kickoff of the barbecue season . We're invited to a grill party in the park tomorrow .
Person2:Sounds good . What do we need to bring ?
Person1: We need to buy some buns for the hot dogs and hamburgers , and I'm making potato salad .
Person2:I'll dig out the Frisbee and my kite from Taiwan .
informal