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:       How old are you , Su ? 
 Person2:I am seven . 
 Person1:        I see , you have seven candles on the cake . 
 Person2:Yes , I am seven . I am a big girl now . 
 Person1:        We will have a party here , right ? 
 Person2:Yes , come on , and we will have fun . 

informal