Problem Statement

In a sequence of $N positive integers a = (a_1, a_2, \dots, a_N),$ how many different integers are there?

Input

Input is given from Standard Input in the following format:
N
$a_1 \ldots a_N$

Output

Print the answer.

Constraints

• $1 \leq N \leq 1000$
• $1 \leq a_i \leq 10^9$ $, (1 \leq i \leq N)$
• All values in input are integers.

Sample Input 1

6
1 4 1 2 2 1

Sample Output 1

3

There are three different integers: 1, 2, 4.

Sample Input 2

1
1

Sample Output 2

1

Sample Input 3

11
3 1 4 1 5 9 2 6 5 3 5

Sample Output 3

7

见题面 Input 部分

见题面 Output 部分