#include <fstream>
#include <algorithm>
#define Nmax 100001
using namespace std;
long long a[Nmax], N;
int main() {
    ifstream f("gravitatie.in");
    ofstream g("gravitatie.out");
    f >> N;
    for(int i = 0; i < N; ++i) {
        f >> a[i];
    }
    sort(a, a + N);
    int sol = 1;
    for(int i = 1; i < N; ++i) {
        if(a[i] != a[i-1])
            ++sol;
    }
    g << sol;
    return 0;
}