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

public class DWITE5 {
		public static void main (String [] args) throws IOException {
			BufferedReader inBuff = new BufferedReader(new FileReader("DATA5.txt"));
			PrintWriter outPrint = new PrintWriter(new FileWriter("OUT5.txt"));
			String total = "", input = "";
			for (int i = 0; i< 1; i++) {
				int count = 0;
				int n = Integer.parseInt(inBuff.readLine());
				int z = Integer.parseInt(inBuff.readLine());
				int [] list = new int [z*2];

					for (int j = 0; j< z; j++) {
						input = inBuff.readLine();
						total += input+ " ";
					}						
				
					StringTokenizer st = new StringTokenizer(total, " ");
					int zzz = 0;
					System.out.println(total);
					while (st.hasMoreElements()) {
						list[zzz] = Integer.parseInt(st.nextToken());
						zzz++;
					}
				
				int [] check = new int [n+1];
				for (int y = 0; y < check.length; y++) {
					check[y] = 0;
				}
				for (int a = 0; a < list.length; a++) {
					for (int h = 0; h < n+1; h++) {
						if (list[a] == h);
						check[h]++;
					}
				}
					for (int b = 0; b < n; b++) {
						if (check[b] == 1);
						count++;
					}
					outPrint.println(count);
			}


	
			
		
			outPrint.close();
		}
}