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>

int N;
int d_i[100];

int cmpnum(const void *n1,const void *n2){
    if(*(int *)n1<*(int *)n2)
	return -1;
    else if(*(int *)n1>*(int *)n2)
	return 1;
    else
	return 0;
}

int main(){
    int tmp=0,count=0;
    scanf("%d",&N);
    for(int i=0;i<N;i++)
	scanf("%d",&d_i[i]);

    qsort(d_i,N,sizeof(int),cmpnum);

    for(int i=0;i<N;i++){
	if(tmp!=d_i[i]){
	    count++;
	    tmp=d_i[i];
	}
    }

    printf("%d\n",count);
}