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: Consider Input: Person1: There will be another sandstorm here tomorrow .
Person2:It's the fourth one this year . Isn't it horrible .
Person1: Yes . We should plant more trees and grass to stop the sand from spreading .
Person2:It may take many years for the trees to grow . I hope people will stop cutting down trees .
Person1: But we need the wood .
Person2:But we can't destroy our forests to get the wood .

Output: informal

Input: Consider Input: Person1: Here's the picture of my family .
Person2:Can you point out your mother for me ?
Person1: OK.She ' s near-sighted , with a pair of glasses on her nose.She is the only one wearing glasses in my family .

Output: formal

Input: Consider Input: Person1: How do you feel about teaching my friend how to read ?
Person2:How old is your friend and why doesn't he know how to read ?
Person1: He's 78 and he's a new emigrant from South America and he's never been to school .
Person2:Does he even know how to speak English ?
Person1: No . But I thought that you could start with reading and then go from there .
Person2:That was very thoughtful of you to volunteer me .
Person1: Come on . You're great at teaching and I know you will love him . He's adorable !
Person2:Oh , all right . Have him come over here for dinner . But you get to make dinner !
Output: formal