Problem:
Score : 200 points

Problem Statement

An X-layered kagami mochi (X ≥ 1) is a pile of X round mochi (rice cake) stacked vertically where each mochi (except the bottom one) has a smaller diameter than that of the mochi directly below it. For example, if you stack three mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, you have a 3-layered kagami mochi; if you put just one mochi, you have a 1-layered kagami mochi.

Lunlun the dachshund has N round mochi, and the diameter of the i-th mochi is d_i centimeters. When we make a kagami mochi using some or all of them, at most how many layers can our kagami mochi have?

Constraints

1 ≤ N ≤ 100

1 ≤ d_i ≤ 100

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
d_1
:
d_N

Output

Print the maximum number of layers in a kagami mochi that can be made.

Sample Input 1

4
10
8
8
6

Sample Output 1

3

If we stack the mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, we have a 3-layered kagami mochi, which is the maximum number of layers.

Sample Input 2

3
15
15
15

Sample Output 2

1

When all the mochi have the same diameter, we can only have a 1-layered kagami mochi.

Sample Input 3

7
50
30
50
100
50
80
30

Sample Output 3

4

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;
namespace Solution
{
    class Solution
    {
        static void Main(string[] args)
        {
            int n = int.Parse(System.Console.ReadLine());
            int[] x = new int[n];
            for(int i = 0; i < n; i++)
            {
                x[i] = int.Parse(System.Console.ReadLine());
            }
            Array.Sort(x);
            int tmp = x[0];
            for (int i = 1; i < n; i++)
            {
                if (tmp == x[i]) x[i] = 0;
                else tmp = x[i];
            }
            int count = 0;
            for(int i = 0; i < n; i++)
            {
                if (x[i] != 0) count++;
            }
            System.Console.WriteLine(count);
        }
    }
}