#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

const int NMAX = 1000001;

int n, m;
vector<int> Muchii[NMAX];
bool viz[NMAX];

void citire()
{
    int x, y;
    f >> n >> m;
    for(int i = 0; i < m; i++)
    {
        f >> x >> y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }
}

void DFS(int nod)
{
    viz[nod] = 1;
    for(int i = 0; i < Muchii[nod].size(); i++)  ///parcurgem vectorul de muchii al nodului curent
    {
        int vecin = Muchii[nod][i];
        if(viz[vecin] == 0)
            DFS(vecin);
    }
}

int main()
{
    int nr_comp_conexe = 0;
    citire();
    //
    for(int i = 1; i <= n; i++)
    {
        if(viz[i] == 0)        ///daca dupa un DFS gasim un nod nevizitat inseamna ca am mai gasit o componenta conexa
        {
            nr_comp_conexe++;
            DFS(i);
        }
    }
    //
    g << nr_comp_conexe;
    return 0;
}