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

using namespace std;

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

const int NLIM = 100005;
bool vizitat[NLIM];
vector<int> Muchii[NLIM];
int N, M;
int insule = 0;

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()
{
    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;
}