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:       Helen , did you hear I ’ m having a party ? Next Saturday in my place .  
 Person2:I may have something on that day , but thanks for inviting me .  
 Person1:        Well , drop by if you can .  
 Person2:I will , do you want me to bring anything ?  
 Person1:        No , just bring yourself . I hope to see you there . 

formal