#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <cmath>
#include <map>
#include <queue>
#include <iomanip>
#include <set>
#include <tuple>
#define mkp make_pair
#define mkt make_tuple
#define rep(i,n) for(int i = 0; i < (n); ++i)
using namespace std;
typedef long long ll;
const ll MOD=1e9+7;

int main(){
  int N;
  cin>>N;
  vector<ll> A(N);
  rep(i,N) cin>>A[i];

  sort(A.begin(),A.end());
  A.erase(unique(A.begin(),A.end()),A.end());

  cout<<A.size()<<endl;

  return 0;
}

