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:       Hi , Cindy . I thought I ’ d missed you . 
 Person2:Oh , I am very sorry , Hans . Thank you for waiting for me . You must have been here a long time already . 
 Person1:        It ’ s all right . 
 Person2:I was caught in the heavy rain , or I would have come earlier . I am sorry I kept you waiting . 
 Person1:        I was in a comfortable place , so really , it ’ s no problem . I am happy to see you . Did the rain hold you up long ? 
 Person2:Yes . When I came out of the subway , it was raining cats and dogs . And I forgot my umbrella . So I had to wait for the rain to let up . 
 Person1:        I totally understand . 

informal