include <bits/stdc++.h>

using namespace std;

int main() { int n; cin >> n; int a[n]; int x[100001]= {},c=0;; for (int i = 0; i < n; ++i) { cin >> a[i]; x[a[i]]++; } for (int i=0; i<= 1e5; i++) { if (x[i]!=0) { c++; } } cout<<c; }