100851: [AtCoder]ABC085 B - Kagami Mochi

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