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 , Tina , I've got good news . I have successfully passed the first two rounds of interview with ABC Company . They informed me to go to the final round next Monday . It looks very promising .  
 Person2:That is awesome . Congratulations ! I know you can make it .  
 Person1:        Thanks . Let's go for a celebration this evening . Are you free ?  
 Person2:Yes . Wait for me at the cafe down my office building . Say 5 PM , ok ?  
 Person1:        No problem . See you !  
 Person2:See you ! 

informal