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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int cmp(const void *a, const void *b)
{
        int x = *(int *)a;
        int y = *(int *)b;

        if (x < y) {
                return -1;
        } else if (x == y) {
                return 0;
        } else {
                return 1;
        }
}

int main(void)
{
        int n, i, ans = 0;
        int *list;

        scanf("%d", &n);
        list = calloc(sizeof(int), n);
        for (i = 0; i < n; i++) {
                scanf("%d", &list[i]);
        }
        qsort(list, n, sizeof(int), cmp);

        ans++;
        for (i = 1; i < n; i++) {
                if (list[i] == list[i - 1]) {
                        continue;
                }
                ans++;
        }
        printf("%d\n", ans);
        return 0;
}