#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int NLIM=100005;
int N,M,x,y,vizitat[NLIM],insule=0;
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]==0) DFS(Vecin);
    }
}
void citire()
{
    fin >> N >> M;
    for (int i=1;i<=M;i++)
    {
        fin >> x >> y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }
}
int main()
{
    citire();
    for (int i=1;i<=N;i++)
    {
        if (vizitat[i]==0)
        {
            insule=insule+1;
            DFS(i);
        }
    }
    fout << insule;
}