# The first integer represents the number of pages.
# Subsequent integers constitute the reference stream.
# The reference stream consists of a list of pages which 
# will be accessed in the order from left to right.

28 1 2 3 4 1 2 5 1 2 3 4 5 2 6 7 6 8 6 9 6 7 6 10 9 8 6 5 4