include <bits/stdc++.h>

using namespace std; int main() { int n; set<int>set1; cin>>n;

for(int i=0; i<n;i++){ int m; cin>>m; set1.insert(m); }

cout<<set1.size();

}

include <bits/stdc++.h>

using namespace std;

int main() { int n; cin>>n; set<int> set1; for(int i = 0 ; i < n ;i++) { int m ; cin>> m ; set1.insert(m) ;

}
    cout<<set1.size();

}