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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long long unsigned int llui;
typedef long long int lli;
typedef long double float64;
typedef pair<int,int> ii;
typedef vector<ii> vii;
typedef vector<int> vi;
typedef vector< vector<int> > vvi;

#define INF 1000000000
#define MOD 1000000007
#define EPS 1e-9
#define DEBUG(x) cout<< '>' << #x << ':' << x << "\n";
#define all(x) (x).begin(), (x).end()
#define SORT(x) sort((x).begin(),(x).end())
#define UNIQUE(x) (x).erase(unique((x).begin(),(x).end()),(x).end())
#define tr(container, it) \
    for(typeof(container.begin()) it = container.begin(); it != container.end(); it++) 


// #define sz(a) int((a).size())
// #define pb push_back
// #define fill(a,v) memset(a,v,sizeof a)


#define trace(x) cout << '>' << #x << ':' << x << endl;
#define trace2(x,y) cout<< '>' << #x << ':' << x << " | " << #y << ':' << y << endl;

#define trace3(x,y,z) cout<< '>' << #x << ':' << x \
        << " | " << #y << ':' << y <<" | " << #z << ':' << z << endl;

#define trace4(x,y,z,w) cout<< '>' << #x << ':' << x \
    << " | " << #y << ':' << y <<" | " << #z << ':' << z << " | " << #w << ':' << w << endl;



inline int two(int n) { return 1 << n; }
inline int test(int n, int b) { return (n>>b)&1; }
inline void set_bit(int & n, int b) { n |= two(b); }
inline void unset_bit(int & n, int b) { n &= ~two(b); }
inline int last_bit(int n) { return n & (-n); }
inline int ones(int n) { int res = 0; while(n && ++res) n-=n&(-n); return res; }

#define LSOne(S) (S&(-S))

const double pi = acos(-1);


template<class T> inline T gcd(T a,T b) //NOTES:__gcd(0,0) gives exception
  {if(a<0)return gcd(-a,b);if(b<0)return gcd(a,-b);return (b==0)?a:gcd(b,a%b);}

int cmp(double x, double y = 0, double tol = EPS) {
    return (x <= y + tol) ? (x + tol < y) ? -1 : 0 : 1;
}

/////////////////////////////////////////////////////////////////////

/*bool sortby(const pair<int,int> &a,const pair<int,int> &b)
{
    return (a.first < b.first);
}*/

const int MAX_N = 4123;

int arr[MAX_N];
 
int main() {
	int N,x;
	scanf("%d",&N);
	set<int> S;
	for(int i=0;i<N;i++){
		scanf("%d",&x);
		S.insert(x);
	}
	printf("%d",S.size());
	return 0;
}