#include <iostream>
#include <fstream>

using namespace std;

ifstream f ("dfs.in");
ofstream g ("dfs.out");

int n, m;
bool a[10001][10001], viz[10001];

void Citire()
{
    f >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        int x, y;
        f >> x >> y;
        a[x][y] = a[y][x] = 1;
    }
}

void DFS(int start)
{
    viz[start] = 1;
    for (int i = 1; i <= n; i++)
    {
        if (a[start][i] == 1 && viz[i] == 0)
        {
            DFS(i);
        }
    }
}

int main()
{
    Citire();

    int insule = 0;
    for (int i = 1; i <= n; i++)
    {
        if (viz[i] == 0)
        {
            insule++;
            DFS(i);
        }
    }
    g << insule;
}