#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 100000
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int N,M,contor;
bool vizitat[NMAX];
vector<int> Muchii[NMAX];
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]==false)
        {
            contor++;
            DFS(i);
        }
    }
}
int main()
{
    Citire();
    fout<<contor;
    return 0;
}