#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

const int nmax=100000;

ifstream f("dfs.in");
ofstream g("dfs.out");

vector <int> Muchii[nmax];

int N,M;
bool viz[nmax];
int insule=0;

void dfs(int nod)
{
    viz[nod] = true;
    for(unsigned int i=0; i<Muchii[nod].size() ; i++)
    {
        int vecin=Muchii[nod][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}

void citire()
{
    f>>N>>M;
    for(int i=0;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(!viz[i])
        {
            insule++;
            dfs(i);
        }
    }
}
int main()
{
    citire();
    g<<insule;
    return 0;
}