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: I am calling to tell you that you are hired by our company .
Person2:I really appreciate your offer , but I have to decline it , because I have already taken another job which I prefer to work in .
Person1: You are welcome , Please call me if you change your mind .
Person2:I will . Thank you .
informal