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 Ruby (2.3.3) (judge verdict: Accepted)

# n 個の整数が与えられます。
# この中に、何種類の異なる値があるでしょうか。

# 与えられる整数の数を取得
n = gets.chomp.to_i

# 与えられた整数を1つずつ格納する配列を宣言し、格納
nums = Array.new
n.times do |i|
    input = gets.to_i
    nums[i] = input
end

# 既に格納されている値を、再び格納しない配列を宣言し、与えられた整数を格納
nums_diff = Array.new
n.times do |i|
    unless nums_diff.include?(nums[i])
        nums_diff << nums[i]
    end
end

# 結果を出力
puts nums_diff.count