#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
ifstream f("intrare.in");
ofstream g("iesire.out");

const int Nlim=100000;
int N,M;
bool vizitat[Nlim];
int insule = 0;
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;
    f>>y;
    Muchii[x].push_back(y);
    Muchii[y].push_back(x);
    }
for(int i=1;i<=N;i++)
    {
        if(!vizitat[i])
        {
        insule++;
        DFS(i);
        }
    }

}

int main()
{
    citire();
    g<<insule<<"\n";
    return 0;
}