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: Mark , you are not telling me the truth . Now why ?
Person2:Promise you are not going to be angry ?
Person1: Yes , all right . So why ? Go on then . Say it . Oh , really , Mark . I promise I'm not going to be angry . Now why were you late ?
Person2:I forgot .
Person1: You forgot ? You ...
Person2:Ah , ah , you promised , and remember ?
informal