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

using namespace std;

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

int const NLIM = 100005;
int N, M;
int insule;
bool vizitat[NLIM];
vector <int> Muchii[NLIM];

void DFS(int Nod)
{
    vizitat[Nod] = 1;
    for(unsigned int i = 0; i < Muchii[Nod].size(); ++ i)
    {
        int Vecin = Muchii[Nod][i];
        if(!vizitat[Vecin])
            DFS(Vecin);
    }

}

void Citire()
{
    int x, y;
    in >> N >> M;
    for(int i = 1; i <= M; ++ i)
    {
        in >> 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();
    out << insule;
    return 0;
}