The recent All-Berland Olympiad in Informatics featured n participants with each scoring a certain amount of points.

As the head of the programming committee, you are to determine the set of participants to be awarded with diplomas with respect to the following criteria: 

  * At least one participant should get a diploma. 
  * None of those with score equal to zero should get awarded. 
  * When someone is awarded, all participants with score not less than his score should also be awarded. 



Determine the number of ways to choose a subset of participants that will receive the diplomas.

Input

The first line contains a single integer n (1 ≤ n ≤ 100) — the number of participants.

The next line contains a sequence of n integers a1, a2, ..., an (0 ≤ ai ≤ 600) — participants' scores.

It's guaranteed that at least one participant has non-zero score.

Output

Print a single integer — the desired number of ways.

Examples

Input

4
1 3 3 2


Output

3


Input

3
1 1 1


Output

1


Input

4
42 0 0 42


Output

1

Note

There are three ways to choose a subset in sample case one.

  1. Only participants with 3 points will get diplomas. 
  2. Participants with 2 or 3 points will get diplomas. 
  3. Everyone will get a diploma! 



The only option in sample case two is to award everyone.

Note that in sample case three participants with zero scores cannot get anything.
import java.util.Scanner;

public class zadacha_a {

	static int n_1, k;
	static int[] a;
	private static Scanner scan;
	
	
	public static void main(String[] args) {	
		scan = new Scanner(System.in);
		n_1 = scan.nextInt();
		a = new int [n_1];
		
		for (int i=0; i<n_1; i++) {
			a[i] = scan.nextInt();
		}
		
		for (int i = 0; i < (n_1-1); i++) {//���������� ������� ������� ��� ������ �������� �������
			for (int j=0; j < ((n_1-1)-i); j++) {
				if (a[j] >= a[j+1]) {
					k = a[j];
					a[j] = a[j+1];
					a[j+1] = k;
				}
			}
		}
		
		k=0;
		
		for (int i=0; i<n_1-1; i++) {
			if ((a[i] == a[i+1]) && (a[i]!=0)) {
				k++;
			}
			
			if (a[i] == 0) {
				k++;
			}
		}
		
		System.out.println(n_1 - k);
	}
}
