#include <algorithm>
#include <vector>
#include <bitset>
using namespace std;

#define pb push_back
#define DIM 100005

vector <int> g[DIM];
bitset <DIM> viz;
int n,m,nrcc;

void read ()
{
    int i,x,y;

    scanf ("%d%d",&n,&m);
    for (i=1; i<=m; ++i)
    {
        scanf ("%d%d",&x,&y);
        g[x].pb (y);
        g[y].pb (x);
    }
}

void df (int nod)
{
    vector <int> :: iterator it;

    viz[nod]=1;
    for (it=g[nod].begin (); it!=g[nod].end (); ++it)
        if (!viz[*it])
            df (*it);
}

void solve ()
{
    int i;

    for (i=1; i<=n; ++i)
        if (!viz[i])
        {
            ++nrcc;
            df (i);
        }
    printf ("%d",nrcc);
}

int main ()
{
    freopen ("dfs.in","r",stdin);
    freopen ("dfs.out","w",stdout);

    read ();
    solve ();

    return 0;
}