#include <bits/stdc++.h>
using namespace std;
 
int main() {
    int n;
    cin >> n;
    vector<int> a(n);
 
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    int max_val = *max_element(a.begin(), a.end());
    vector<int> res(max_val + 1, 0);
 
    for (int i = 0; i < n; i++) {
        res[a[i]]++;
    }
 
    int c = 0;
    for (int i = 0; i < res.size(); i++) {
        if (res[i] > 0) c++;
    }
 
    cout << c << endl;
 
    return 0;
}
 

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