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

using namespace std;

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

int n,m,viz[100005],nrc,l[100005];

vector <int> a[100005];

void citire_graf()
{
    f>>n>>m;
    int x,y;
    for(int i=1;i<=m;++i)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

void parcurgere_adancime(int nod)
{
    viz[nod]=nrc;
    for(int i=0;i<l[nod];++i)
    {
        if(viz[a[nod][i]]==0)
            parcurgere_adancime(a[nod][i]);
    }
}

int main()
{
    citire_graf();
    for(int i=1;i<=n;++i)
        l[i]=a[i].size();
    for(int i=1;i<=n;++i)
    {
        if(viz[i]==0)
        {
            nrc++;
            parcurgere_adancime(i);
        }
    }
    g<<nrc;
    return 0;
}