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

ifstream f ("dfs.in");
ofstream g ("dfs.out");
const int N=100001;
int n, m, viz[N];
vector <int> a[N];

void citire ()
{
    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 dfs (int x)
{
    viz[x]=true;
    for (int i=0; i<a[x].size(); i++)
    {
        if (!viz[a[x][i]]) dfs (a[x][i]);
    }
}

void rezolva ()
{
    int nr=0;
    for (int i=1; i<=n; i++)
        if (!viz[i])
        {
            dfs(i); nr++;
        }
    g<<nr<<'\n';
}

int main ()
{
    citire ();
    rezolva ();
    return 0;
}