import java.util.*;
class Main
{
    public static void main(String[] args) 
    {
        Scanner s=new Scanner(System.in);
        int t=s.nextInt();
        while(t-->0) 
        {
            int n=s.nextInt(); 
            Set<Integer>elements=new HashSet<>();
            for(int i=0;i<n;i++) 
            {
                int num=s.nextInt();
                elements.add(num); 
            }
            System.out.println(elements.size());
        }
    }
}

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Mgo1CjEgMSAxIDEgMQo1CjEgMiAzIDEgMg==

2
5
1 1 1 1 1
5
1 2 3 1 2