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 ABC085B
{
    class Program
    {
        static void Main(string[] args)
        {
            var count = int.Parse(Console.ReadLine());
            var d = new List<int>();
            for(int i = 0; i < count; i++)
            {
                d.Add(int.Parse(Console.ReadLine()));
            }
            var sorted = d.OrderBy(v => v).ToArray();

            var result = new List<int>();
            for(int i = 1; i < sorted.Count(); i++)
            {
                if(sorted[i] == sorted[i - 1])
                {
                    continue;
                }

                result.Add(sorted[i]);
            }

            if (!result.Contains(sorted[0]))
            {
                result.Add(sorted[0]);
            }

            Console.WriteLine($"{result.Count()}");
        }
    }
}