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 int_sort(const void *a ,const void *b){
  if(*(int*)a < *(int*)b){
    return -1;
  }
  else
  if(*(int*)a == *(int*)b){
    return 0;
  }
  return 1;
}
int main(void){
  size_t data_cnt , i;
  int n;
  scanf("%d",&n);
  int d[n];

  data_cnt = sizeof(d)/sizeof(d[0]);
  for(i=0;i<data_cnt;i++){
    scanf("%d",&d[i]);
  }

/*  for(i=0;i<data_cnt;i++){
    printf("d[%d]=%d\n",i,d[i]);
  }*/
  qsort((void*)d,data_cnt,sizeof(d[0]),int_sort);
/*  for(i=0;i<data_cnt;i++){
    printf("d[%d]=%d\n",i,d[i]);
  }*/
  int cnt=0;
  for(i=0;i<data_cnt;i++){
    if(d[i]!=d[i+1]){
      cnt++;
    }
  }
  printf("%d",cnt);
  return 0;
}