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.Collections.Generic;
using System.Linq;
namespace Program
{
    class Test1
    {
        static void Main()
        {
            int count = 1;
            string a = Console.ReadLine();
            int N = int.Parse(a);
            string[] bb = new string[N];
            for (int i=0;i<N;i++ )
            {
                bb[i] = Console.ReadLine();
            }
            int[] bbb = bb.Select(int.Parse).ToArray();
            Array.Sort(bbb);
            List<int> aaa = new List<int>(bbb);
            aaa.RemoveAt(0);
            aaa.Add(bbb[0]);
            for (int i=1;i<bbb.Length;i++)
            {
                if (bbb[i - 1] < bbb[i])
                {
                    aaa.RemoveAt(0);
                    count++;
                }
            }
            Console.WriteLine(count);
        }
    }
}