#include <iostream>
#include <stdbool.h>
#include <fstream>
#include <vector>

using namespace std;

void dfs(int nodStart, int nrNoduri, vector <int> *lista, bool *vizitat){

    vizitat[nodStart] = true;

    for ( unsigned int i = 0; i < lista[nodStart].size(); i++)
                if ( vizitat[lista[nodStart][i]] == false )
                       dfs(lista[nodStart][i],nrNoduri,lista,vizitat);

}

int main(){

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


        int nrNoduri = 0, nrMuchii = 0;

        fin >> nrNoduri >> nrMuchii;

        vector <int> lista[nrNoduri + 5];

        bool *vizitat;
        vizitat = new bool[nrNoduri + 5];

        for (int i = 1; i <= nrMuchii; i++){

                int a, b;

                fin >> a >> b;

                lista[a].push_back(b);
                lista[b].push_back(a);
        }


    for ( int i = 1; i <= nrNoduri; i++){
            vizitat[i] = false;
    }
    
    int nrComponente = 0;

    for ( int i = 1; i <= nrNoduri; i++)
            if ( vizitat[i] == false ){
                    dfs(i,nrNoduri,lista,vizitat);
                    nrComponente++;

            }

     fout << nrComponente;

    return 0;

}