#include <bits/stdc++.h>

using namespace std;

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

#define NMAX 100001

class Graf{
private:

    int n, m;
    vector<int> v[NMAX];
    bitset<NMAX> vizitat;

public:
    void adauga_nod(int, int);
    void citire_graf_neorientat();
    void dfs(int);
    int nr_componente_conexe();
};


void Graf::citire_graf_neorientat(){
    int nrNoduri, nrMuchii;
    fin >> nrNoduri >> nrMuchii;
    this-> n = nrNoduri;
    this-> m = nrMuchii;

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

void Graf::dfs(int nod){
    vizitat[nod] = true;
    for (auto it: v[nod])
        if(!vizitat[it])
            dfs(it);
}


int Graf::nr_componente_conexe(){
    int compConexe = 0;
    for (int i=1; i<= this->n ;i++)
        if(!vizitat[i])
    {
        dfs(i);
        compConexe++;
    }
    return compConexe;
}


int main()
{
    Graf G;
    G.citire_graf_neorientat();
    fout<<G.nr_componente_conexe();
    return 0;
}