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 , Jason !  
 Person2:Hi , Linda . I have two concert complimentary tickets . Will you go with me tonight ?  
 Person1:        With the greatest pleasure ! Where is the concert held this evening ?  
 Person2:It will be held at the Central Music Hall .  
 Person1:        What is on the program ?  
 Person2:It ’ s a piano solo . I'm fond of piano , you know .  
 Person1:        Hah ! OK . Let ’ s go together !  
 Person2:Let ’ s meet at the park at 6:00 .  
 Person1:        See you then . 

informal