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:       Happy birthday , Aims !  
 Person2:Thank you , Lisa .  
 Person1:        Here is a present for you . I hope you like it .  
 Person2:Oh , great ! I love it ! You know I've been expecting this for a long time .  
 Person1:        I'm very glad to hear that .  
 Person2:Come here ; let me introduce some friends to you . 

informal