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:       Mr.Keller , may I call at your home sometime the week ? 
 Person2:Oh , certainly.When would you like to come ? 
 Person1:        Well , when will it be convenient for you ? 
 Person2:This weekend would be OK with me . 

formal