#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m;
const int NLIM=100005;
bool vizitat[NLIM];
int insule;
vector <int> Muchii[NLIM];
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()
{
    f>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x, y;
        f>>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);
        }
}
int main()
{
    Citire();
    g<<insule<<'\n';
    return 0;
}