PP2: Week 9,10: May 17 - 30

n integers are given. How many of them are different?

Input

The first line contains amount of numbers n (1 ≤ n ≤ 10⁶). Second line contains n integers, each of them is no greater than 2 * 10⁹ by absolute value.

Output

Print the amount of different numbers.

Time limit 3 seconds

Memory limit 128 MiB

Input example #1

1
3

Output example #1

Input example #2

5
9 15 22 15 22

Output example #2

PP2: Week 9,10: May 17 - 30

Different-different

Input

Output