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'.

Ex Input:
Person1: All right . But these are black and I don ' t like black shoes . They ' re dull .
Person2:Well , black is a better color than pink . Pink ' s for girls .
Person1: Then why are you wearing black shoes ?
Person2:Because ... oh , all right . You win . Let ' s pay for them and go .
Person1: Hey , thanks , mum .

Ex Output:
informal

Ex Input:
Person1: Hi ! Someone has reported a fault on one of your copiers .
Person2:That's right . I'm glad you're here . It hasn't been working properly for the last few days .
Person1: When was it serviced ?
Person2:Just a couple of weeks ago . It's usually very reliable .
Person1: What's actually wrong with it ?
Person2:Well , it's making a strange noise when we try to change paper trays .
Person1: I'm sure it's nothing serious , probably just a minor fault . I'll have a look at it .

Ex Output:
formal

Ex Input:
Person1: David , what have you been up to lately ?
Person2:I went on a trip with my family last week .
Person1: Really ? Where did you go ?
Person2:We went to Europe .
Person1: What cities did you go to ?
Person2:London , Paris and a few other cities .
Person1: Did you go to Berlin ?
Person2:No , We didn't go there . I'd like to go there next time .
Person1: I think this summer is a good time to visit Berlin . It's a beautiful place and the people there are very nice .
Person2:That's what I've heard .
Person1: I went there last year . If you want , I can give you some information I have about the city .
Person2:Thanks .

Ex Output:
informal