#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  long long t;
  cin >> t;
  while (t--) {
    long long n;
    cin >> n;
    long long a[n];
    set<long long> s;
    for (long long i = 0; i < n; i++) {
      cin >> a[i];
      s.insert(a[i]);
    }
    cout << s.size() << "\n";
  }
}
