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:       Is everything ready for Billy ’ s birthday party ? 
 Person2:Yes . I ’ Ve finished making the birthday cake and I ’ Ve put all the things on the table . Did you find the party hats ? 
 Person1:        Yes , I did . I ’ Ve put one on the table for each child . I put up the big “ happy birthday ” sign too . 
 Person2:Thanks . Do you think we have enough for the kids to eat and drink ? 
 Person1:        I ’ m sure of that . There ’ s enough food here to feed an army ! 
 Person2:That birthday cake looks wonderful , but you haven ’ t put any candles on it yet . 
 Person1:        Thanks for reminding me . I ’ Ve prepared some party games for the children too . 
 Person2:I ’ Ve brought a tape with lots of children ’ s songs on it . 
 Person1:        Hopefully , that will keep everyone happy . 

informal