Definition: 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'.
Input:  Person1:       Hello , I've got a letter here that I'd like to post . 
 Person2:Yes , where's it to , madam ? 
 Person1:        Well , the letter is going to a friend of mine in America and it's quite urgent . It really needs to be posted today , so here you are . 
 Person2:You want to send it airmail , madam ? 
 Person1:        I do want to send it airmail , yes . 

formal