As everybody knows, there are a lot of stores in skyscrapers, it's the
favourite place of glamorous girls. Blonde Cindy loves only one thing —
the shopping. Today is one of the best days, she's going shopping to the new
skyscraper “Prisma”. At first she decided to visit all the stores. But
actually the “Prisma” is so large that you can find not just one store of
each brand. Every time when Cindy found the brand, she has visited before,
she told “Bayan”, and went on shopping.
Cindy saw all the stores in the “Prisma”. So how many times did she tell “Bayan”?
First line contains single integer N representing the number of stores in
the “Prisma” (1 ≤ N ≤ 1000).
In each of next N lines the brand of store is written. The brands are the strings of
Latin letters and blanks. The length of the string is from 1 to 30.
There are no brands, that differ only in register.
Print the number of stores, Cindy didn't visit.
Lady and Gentleman City
Problem Author: Vladimir Yakovlev
Problem Source: The XIIth USU Programing Championship, October 6, 2007