import java.io.*;
import java.util.*;

public class seat {

	/**
	 * @param args
	 */
	public static void main(String[] args) throws IOException{
		File f;
		Scanner input;
		
		try {
			f = new File("seat.in");
			input = new Scanner(f);
		} catch (IOException e) {
			e.printStackTrace();
			return;
		}
			
		//get the number of datasets
		int k = input.nextInt();
		
		for (int dataset=0;dataset<k;dataset++) {
			int P = input.nextInt();
			int M = input.nextInt();

			int[] machines = new int[M];
			int m;
			for (m=0;m<M;m++) {
				machines[m] = 0;
			}
			
			int unsuccess = 0;
			
			for (int p=0;p<P;p++) {
				int machine = input.nextInt();
				if (machines[machine-1] == 0)
					machines[machine-1]++;
				else
					unsuccess++;
				
			}
			
			System.out.println("Data Set " + dataset);
			System.out.println(unsuccess);
			if (dataset != k-1)
				System.out.println();
			
	
		}
		
		
	}

}