#include <fstream>
#include <vector>
using namespace std;

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

int N, M;
int insule;
const int NMax = 100005;
bool vizitat[NMax];

using VI = vector <int>;
VI Muchii[NMax];

void Citire();
void DFS(int Nod);

int main()
{
    Citire();
    fout << insule;
}

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()
{
    int x, y;
    fin >> N >> M;

    while (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);
        }

}