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: Want to meet for lunch this Saturday ?
Person2:Sorry , I can ' t . I ' m busy .
Person1: What are you doing ?
Person2:I always do volunteer work on the first Saturday of every month .
Person1: What kind of volunteer work ?
Person2:I help out at the children ' s hospital . I help plan activities .
Person1: Oh , yeah ?
Person2:Yeah . It ' s exciting . This month we ' re doing crossword puzzles .
informal