#include<iostream>
#include <vector> 
#include <algorithm>
using namespace std;
int main(){
    long long int n,a,count{0},temp;
    vector<int> vc;
    cin >> n;
    for(int i=0; i<n; i++){
        cin >> a;
        vc.push_back(a);
    }
    sort(vc.begin(), vc.end());
    for(int i=0; i<n; i++){
        if(vc[i]!=vc[i+1]){
            if(temp==vc[i]){continue;}
                count++;    
        }
        temp = vc[i];
    }
    cout << count << endl;
    return 0;
}