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 PHP (5.6.30) (judge verdict: Accepted)

<?php

$is_honban = 1;

if ($is_honban) {
  //----------------------------------------------------------------------------------
  // Input for honban
  //----------------------------------------------------------------------------------
  $sc = new Scanner();
  $n = $sc->nextInt();
  $d = array();
  for ($i = 0; $i < $n; $i++) {
    $d[] = $sc->nextInt();
  }



} else {
  //----------------------------------------------------------------------------------
  // Input for test
  //----------------------------------------------------------------------------------
  error_reporting(E_ERROR | E_WARNING | E_PARSE);

  $n = 7;
  $d = array(50,30,50,100,50,80,30);



}
//----------------------------------------------------------------------------------
// Main
//----------------------------------------------------------------------------------

$ans = 0;

$dd = array_unique($d);
$ans = count($dd);



//----------------------------------------------------------------------------------
// Output
//----------------------------------------------------------------------------------
out::println($ans);



//----------------------------------------------------------------------------------
// Ref: https://qiita.com/yoshikyoto/items/6924478283dbdd549e4b
//----------------------------------------------------------------------------------
class Scanner {
  private $arr = array();
  private $count = 0;
  private $pointer = 0;
  public function next() {
    if($this->pointer >= $this->count) {
      $str = trim(fgets(STDIN));
      $this->arr = explode(' ', $str);
      $this->count = count($this->arr);
      $this->pointer = 0;
    }
    $result = $this->arr[$this->pointer];
    $this->pointer++;
    return $result;
  }
  public function hasNext() {
    return $this->pointer < $this->count;
  }
  public function nextInt() {
    return (int)$this->next();
  }
  public function nextDouble() {
    return (double)$this->next();
  }
}

class out {
  public static function println($str = "") {
    echo $str . PHP_EOL;
  }
}

?>