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'.

Example Input: Person1: Here's 30 yuan for my ticket .
Person2:Keep it . I'm buying tonight .
Person1: No , you can't do that .
Person2:Sure I can , my treat .
Example Output: informal

Example Input: Person1: Is that true ?
Person2:I guess so . Now Anna's got four kids and another on the way .
Person1: Wow . She looks good for having had that many kids . She's pregnant and wearing Prada !
Person2:That's Anna for you . She keeps up the image of the stylish Italian woman . Here she comes .
Person1: She's glowing . It must be the pregnancy .
Person2:Yeah , or the expensive Italian facial treatments .
Example Output: formal

Example Input: Person1: Mary is such a cautious girl !
Person2:What do you mean by cautious ?
Person1: She never puts words into her mouth , she only repeats the opinions of others .
Person2:Thats a clever way to escape responsibility .
Example Output:
formal