#include <iostream>
#include <string>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <vector>
#include <queue>
#include <deque>
#include <map>
#define range(i,a,b) for(int i=a;i<=b;++i)
#define LL long long
#define rerange(i,a,b) for(int i=a;i>=b;--i)
#define fill(arr,tmp) memset(arr,tmp,sizeof(arr))
using namespace std;
map<int,bool>nn;
int n;
void init(){
cin>>n;
while(n--){
int tmp;
cin>>tmp;
nn[tmp]=true;
}
}
void solve(){
int ans=0;
map<int,bool>::iterator iter;
for(iter=nn.begin();iter!=nn.end();++iter)ans+=(iter->second?1:0);
cout<<ans<<endl;
}
int main() {
init();
solve();
return 0;
}