import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;

public class ComponenteConexe {
    public static void main(String[] args) throws IOException {
        Scanner sc = new Scanner(new File("dfs.in"));
        FileWriter fw = new FileWriter("dfs.out");

        int n;
        long m;
        ArrayList<Integer>[] adj = new ArrayList[(int)1e5 + 1];

        n = sc.nextInt();
        m = sc.nextLong();

        for (int i = 1; i <= n; i++) {
            adj[i] = new ArrayList<>();
        }

        for (int i = 1; i <= m; i++) {
            int x = sc.nextInt();
            int y = sc.nextInt();
            adj[x].add(y);
            adj[y].add(x);
        }

        int[] viz = new int[n + 1];
        int nrCC = 0;
        for (int i = 1; i <= n; i++) {
            if (viz[i] == 0) {
                nrCC++;
                dfs(i, adj, viz);
            }
        }

        fw.write(String.valueOf(nrCC));

        sc.close();
        fw.close();
    }

    private static void dfs(int i, ArrayList<Integer>[] adj, int[] viz) {
        viz[i] = 1;
        for (int j = 0; j < adj[i].size(); j++) {
            if (viz[adj[i].get(j)] == 0) {
                dfs(adj[i].get(j), adj, viz);
            }
        }
    }
}