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:       David , recently I established a travelling forum , and now I want to make a plan to hold the first activity . Where can we go for this time ? 
 Person2:How many members are there in your forum ? 
 Person1:        a dozen . 
 Person2:I think we can visit West Lake . The landscapes are attractive . It is said that just as there is paradise in heaven , there are Su Thou and Hang Thou on earth . 
 Person1:        It's surely worth going to . There are ten famous spots there . 
 Person2:What can we do next after locating the place ? 
 Person1:        Inform my members to prepare for the travelling . And then we can discuss about the travelling costs . 

informal