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'.

[Q]: Person1: Can I help you , sir ?
Person2:I wish to buy a diamond ring .
Person1: How many carats would you like it to be ?
Person2:I want five carats .
Person1: Is this one suitable for you ?
Person2:No , it seems too old-fashioned to my fiancee .
Person1: What about this ?
Person2:It seems too small for me , haven't you got any larger ones ?
Person1: Then you can buy this one . It's very nice and latest in style .
Person2:Oh , this one is perfect .
[A]: informal

[Q]: Person1: It's four o'clock already . I hate to leave , but I think I must .
Person2:Can you stay a little longer ?
Person1: I'm sorry , but I can't .
[A]: informal

[Q]: Person1: Did you go to see Michael last night ?
Person2:Yes , He had just bought a new motorcycle .
Person1: Did he let you ride it ?
Person2:Yes , I tried it and I quite liked it .
Person1: Weren ' t you frightened ?
Person2:Sure . But I still liked it .
Person1: Would you like to buy a motorcycle yourself ?
Person2:No . Although motorcycle is nice , I ' d like to buy a bicycle .
Person1: But why ? Since you like it so much .
Person2:Because bicycles are safer .
[A]:
informal