#include <iostream>
#include <vector>
#include <fstream>



using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int nlim=100005;

int n,m;
unsigned insule=0;
bool vizitat[nlim];
vector <int> muchie[nlim];

void dfs(int nod)
{
    vizitat[nod]=true;
    for(unsigned int i=0;i<muchie[nod].size();i++)
    {
        int v=muchie[nod][i];
        if(!vizitat[v]) dfs(v);
    }
}

void citire()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        muchie[x].push_back(y);
        muchie[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        if(!(vizitat[i])) insule++,dfs(i);
    }
}
int main()
{
    citire();
    fout<<insule;
}