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 Common Lisp (SBCL 1.1.14) (judge verdict: Wrong Answer)

(defun card-game-for-two (n a)
  (let ((alice 0)
        (bob 0))
    (setf a (sort a #'>))
    (dotimes (i n)
      (if (zerop (rem i 2))
          (setf alice (+ alice (aref a i)))
          (setf bob (+ bob (aref a i)))))
    (- alice bob)))

(defun create-data ()
  (let* ((n (read))
         (a (make-array `(,n))))
    (dotimes (i n)
      (setf (aref a i) (read)))
    (values n a)))

(multiple-value-bind (n a) (create-data)
  (format t "~A~%" (card-game-for-two n a)))