#include <iostream>
#include <vector>
#include <fstream>

using namespace std;

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

int n, m;
vector <int> v[100001];
bool viz[100001];

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

void DFS(int start)
{
    viz[start] = true;
    for (int i = 0; i < v[start].size(); i++)
    {
        if (viz[v[start][i]] == false)
        {
            DFS(v[start][i]);
        }
    }
}

int main()
{
    Citire();

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