1. 

package acm_11087_divisibility_testing;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;
import java.util.TreeSet;

/**
 * FWP, AusgewŠhlte Probleme aus dem ACM Programming Contest, SS10 
 * Problem: acm_11087_divisibility_testing
 * Link: 
 * 
 * @author Martin Lambeck
 * @version 1.0, 14.10.2010
 * 
 * Method : modulo restklassen
 * Status : Accepted
 * Runtime: 2.336
 */


public class Main
{
	static Scanner sc = new Scanner(System.in);
	static ArrayList<TreeSet<Integer>> lst = new ArrayList<TreeSet<Integer>>(501);
	static int tcase = 0;
	
	public static void main(String... args)
	{

		for (int i = 0; i < 500; i++)
			lst.add(new TreeSet<Integer>());

		
		int cases = sc.nextInt();

		for (int i = 0; i < cases; i++)
			testcase();
	}

	public static void testcase()
	{
		int n = sc.nextInt();
		int k = sc.nextInt();

		int count = 0;
		
		for (int i = 0; i < k; i++)
			lst.get(i).clear();	

		for (int i = 0; i < n; i++)
		{
			int m = sc.nextInt();
			int mod = ((m % k) + k) % k;
			
			if (((m+m) % k == 0) && lst.get(mod).contains(m))
				count++;
			
			lst.get(mod).add(m);
		}
		
	
		
		for (int i = 0; i < k; i++)
		{
			TreeSet<Integer> lo = lst.get(i);
			TreeSet<Integer> hi = lst.get(i==0 ? 0 : k-i);
			
			Iterator<Integer> hii = hi.iterator();
			
			int hn = Integer.MIN_VALUE;
			int hpos = -1;
			
			for (Integer ln : lo)
			{
				while((hn <= ln) && hii.hasNext())
				{
					hn = hii.next();
					hpos++;
				}
				
				if (hn > ln)
					count += hi.size() - hpos;
			}
		}

		System.out.printf("Case %d: %d%n", ++tcase, count);
	}
}