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:       Congratulations ! Mr . Stuart ! You won the city marathon .  
 Person2:Thank you . I am very excited .  
 Person1:        We are all very proud of you .  
 Person2:I am very happy , too . It was a big game and I won .  
 Person1:        I watched the race with my children . We saw you run to the finish line . We all screamed with excitement .  
 Person2:It was really an exciting moment . 

informal