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

using namespace std;

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

const int NLim = 100005;
int N,M;
bool vizitat[NLim];
vector < int > Muchii[NLim];
int insule = 0;
/*
*1:2 4
*2:1
*3:5
*4:1
*5:3
*6:-
*/
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 += 1;
            DFS(i);
        }
    }

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