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

#define Nmax 100005

using namespace std;

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

bool vizitat[Nmax];
int N, M;

class Graf{
private:
    int Nr_Noduri, Nr_Muchii;
    vector<int> matrice_adiacenta[Nmax];
    
public:
    Graf(int N, int M); // constructor
    /*
    vector < vector<int> > getMatriceAdiacenta()
    {
        return matrice_adiacenta;
    }
    */
    void Citire_Graf_Neorientat();
    void DFS(int nod_Start);
    void Numar_Comp_Conexe();
};

// constructor
Graf :: Graf(int N, int M)
{
    Nr_Noduri = N;
    Nr_Muchii = M;
}

void Graf :: Citire_Graf_Neorientat()
{
    for ( int i = 1; i <= Nr_Muchii; i++ )
    {
        int x, y;
        fin >> x >> y;
        matrice_adiacenta[x].push_back(y);
        matrice_adiacenta[y].push_back(x);
    }
}

void Graf :: DFS(int S)
{
    vizitat[S] = 1;
    for ( int i = 0; i < matrice_adiacenta[S].size(); i++ )
        if ( vizitat[matrice_adiacenta[S][i]] == 0 )
            DFS(matrice_adiacenta[S][i]);
}

void Graf :: Numar_Comp_Conexe()
{
    int nr_comp_conexe = 0;
    for ( int i = 1; i <= Nr_Noduri; i++ )
        if ( !vizitat[i] )
        {
            nr_comp_conexe++;
            DFS(i);
        }
    fout << nr_comp_conexe;
}

int main()
{
    fin >> N >> M;

    Graf G(N, M);
    G.Citire_Graf_Neorientat();

    G.Numar_Comp_Conexe();

    return 0;
}