Distinct Numbers

#include <bits/stdc++.h>

using namespace std;

int n;
set<long long> val;

int main(){
    //freopen("distinctnumbers.in", "r", stdin);

    cin >> n;
    int v;
    for(int i=0; i<n; i++){
        cin >> v;
        val.insert(v);
    }
    cout << val.size() << '\n';

    return 0;
}