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 did your vacation go ? 
 Person2:I traveled the Three Gorges . 
 Person1:        What about the trip ? Do you enjoy yourself ? 
 Person2:Yes , we had a good time . The trip was terrific . We toured the Three Gorges by boat . Its realty exciting ! 
 Person1:        Did your boat float down the river ? 
 Person2:Yes . There are many places where the gorge is very narrow , with steep cliffs on both sides . 
 Person1:        Sounds dangerous . 
 Person2:Yes , but we have life jackets . And we got a real kick out of that . 
 Person1:        What a thrilling trip ! 

informal