#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;

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;
}