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

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int NLIM=10005;

int N, M;
bool vizitat[NLIM];

vector <int> Muchii[NLIM];

int insule=0;

void DFS(int Nod)
{
    vizitat[Nod]=true;
    for(unsigned int i = 0; i < Muchii[Nod].size();i++)
    {
        int Vecin = Muchii[Nod][i];
        if(!vizitat[Vecin])
            DFS(Vecin);
    }
}

void Citire()
{
    fin>>N>>M;
    for(int i=1;i<=M;i++)
    {
        int x, y;
        fin>>x>>y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }
    for(int i=1;i<=N;i++)
    {
        if(!vizitat[i]) {insule++;
                        DFS(i);}
    }
}

int main()
{

    Citire();
    fout << insule << "\n";
    return 0;
}