Description

Problem A - The Problems

HT is drawing up the upcoming midterm. In order to get more ideas, HT asks his TA to prepare n distinct problems. Each problem will be inspected carefully and be graded by its quality, said to be a_i. HT wants to find out how many different kinds of "quality score" are there in the problem set that TA gave to him.

Input

The first line contains an integer n, representing the number of problems TA give to HT.

The second line contains n integers a_i, representing the quality score of each question.

It is guaranteed that :

• testcase #1 : Sample Input
• testcase #2~3 : 1 ≤ n ≤ 100, 1 ≤ a_i ≤ 3
• testcase #4~6 : 1 ≤ n ≤ 100, 1 ≤ a_i ≤ 100
• testcase #7~9 : 1 ≤ n ≤ 100, -100 ≤ a_i ≤ 100
• testcase #10 : 1 ≤ n ≤ 2*10⁵, -10⁵ ≤ a_i ≤ 10⁵

If you can't pass testcase #10 immediately, try to solve another two problems first. 

Output

Please output a line represents the number of different kinds of "quality score" in the problem set.

Sample Input  Download

Sample Output  Download

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