#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 += 1;
            DFS(i);
        }
    }
    fout << insule << "\n";
}
 
int main() {
    Citire();
    return 0;
}